5-(N-fused tricyclic aryl tetrahydroisoquinolin-6-yl) pyridin-3-yl acetic acid derivatives as inhibitors of human immunodeficiency virus replication

ABSTRACT

Disclosed are compounds of Formula I, including pharmaceutically acceptable salts, pharmaceutical compositions comprising the compounds, methods for making the compounds and their use in inhibiting HIV integrase and treating those infected with HIV or AIDS.

CROSS REFERENCE TO RELATED INVENTION

This application is a § 371 of International Application No.PCT/IB2016/054829, filed 10 Aug. 2016, which claims the benefit of U.S.Provisional Application No. 62/204,117, filed 12 Aug. 2015.

FIELD OF THE INVENTION

The invention relates to compounds, compositions, and methods for thetreatment of human immunodeficiency virus (HIV) infection. Moreparticularly, the invention provides novel inhibitors of HIV,pharmaceutical compositions containing such compounds, and methods forusing these compounds in the treatment of HIV infection. The inventionalso relates to methods for making the compounds hereinafter described.

BACKGROUND OF THE INVENTION

Human immunodeficiency virus (HIV) has been identified as theetiological agent responsible for acquired immune deficiency syndrome(AIDS), a fatal disease characterized by destruction of the immunesystem and the inability to fight off life threatening opportunisticinfections. Recent statistics indicate that an estimated 35.3 millionpeople worldwide are infected with the virus (UNAIDS: Report on theGlobal HIV/AIDS Epidemic, 2013). In addition to the large number ofindividuals already infected, the virus continues to spread. Estimatesfrom 2013 point to close to 3.4 million new infections in that yearalone. In the same year there were approximately 1.6 million deathsassociated with HIV and AIDS.

Current therapy for HIV-infected individuals consists of a combinationof approved anti-retroviral agents. Over two dozen drugs are currentlyapproved for HIV infection, either as single agents or as fixed dosecombinations or single tablet regimens, the latter two containing 2-4approved agents. These agents belong to a number of different classes,targeting either a viral enzyme or the function of a viral proteinduring the virus replication cycle. Thus, agents are classified aseither nucleotide reverse transcriptase inhibitors (NRTIs),non-nucleotide reverse transcriptase inhibitors (NNRTIs), proteaseinhibitors (PIs), integrase inhibitors (INIs), or entry inhibitors (one,maraviroc, targets the host CCR5 protein, while the other, enfuvirtide,is a peptide that targets the gp41 region of the viral gp160 protein).In addition, a pharmacokinetic enhancer with no antiviral activity,i.e., cobicistat, available from Gilead Sciences, Inc. under thetradename TYBOST™ (cobicistat) tablets, has recently been approved foruse in combinations with certain antiretroviral agents (ARVs) that maybenefit from boosting.

In the US, where combination therapy is widely available, the number ofHIV-related deaths has dramatically declined (Palella, F. J.; Delany, K.M.; Moorman, A. C.; Loveless, M. O.; Furher, J.; Satten, G. A.; Aschman,D. J.; Holmberg, S. D. N. Engl. J. Med. 1998, 338, 853-860).

Unfortunately, not all patients are responsive and a large number failthis therapy. In fact, initial studies suggest that approximately 30-50%of patients ultimately fail at least one drug in the suppressivecombination. Treatment failure in most cases is caused by the emergenceof viral resistance. Viral resistance in turn is caused by thereplication rate of HIV-1 during the course of infection combined withthe relatively high viral mutation rate associated with the viralpolymerase and the lack of adherence of HIV-infected individuals intaking their prescribed medications. Clearly, there is a need for newantiviral agents, preferably with activity against viruses alreadyresistant to currently approved drugs. Other important factors includeimproved safety and a more convenient dosing regimen than many of thecurrently approved drugs.

Compounds which inhibit HIV replication have been disclosed. See, forexample, the following patent applications: WO2007131350, WO2009062285,WO2009062288, WO2009062289, WO2009062308, WO2010130034, WO2010130842,WO2011015641, WO2011076765, WO2012033735, WO2013123148, WO2013134113,WO2014164467, WO2014159959, and WO2015126726.

What is now needed in the art are additional compounds which are noveland useful in the treatment of HIV. Additionally, these compounds maydesirably provide advantages for pharmaceutical uses, for example, withregard to one or more of their mechanisms of action, binding, inhibitionefficacy, target selectivity, solubility, safety profiles, orbioavailability. Also needed are new formulations and methods oftreatment which utilize these compounds.

SUMMARY OF THE INVENTION

The invention encompasses compounds of Formula I, includingpharmaceutically acceptable salts thereof, as well as pharmaceuticalcompositions, and their use in inhibiting HIV and treating thoseinfected with HIV or AIDS.

By virtue of the present invention, it is now possible to providecompounds that are novel and are useful in the treatment of HIV.Additionally, the compounds may provide advantages for pharmaceuticaluses, for example, with regard to one or more of their mechanism ofaction, binding, inhibition efficacy, target selectivity, solubility,safety profiles, or bioavailability.

The invention also provides pharmaceutical compositions comprising thecompounds of the invention, including pharmaceutically acceptable saltsthereof, and a pharmaceutically acceptable carrier, excipient, and/ordiluent.

In addition, the invention provides methods of treating HIV infectioncomprising administering a therapeutically effective amount of thecompounds of the invention to a patient.

In addition, the invention provides methods for inhibiting HIVintegrase.

Also provided in accordance with the invention are methods for makingthe compounds of the invention.

The present invention is directed to these, as well as other importantends, hereinafter described.

DESCRIPTION OF THE INVENTION

Unless specified otherwise, these terms have the following meanings.

“Alkyl” means a straight or branched saturated hydrocarbon comprised of1 to 10 carbons, and preferably 1 to 6 carbons.

“Alkenyl” means a straight or branched alkyl group comprised of 2 to 10carbons with at least one double bond and optionally substituted with0-3 halo or alkoxy group.

“Alkynyl” means a straight or branched alkyl group comprised of 2 to 10carbons, preferably 2 to 6 carbons, containing at least one triple bondand optionally substituted with 0-3 halo or alkoxy group.

“Aryl” mean a carbocyclic group comprised of 1-3 rings that are fusedand/or bonded and at least one or a combination of which is aromatic.The non-aromatic carbocyclic portion, where present, will be comprisedof C₃ to C₇ alkyl group. Examples of aromatic groups include, but arenot limited to indanyl, indenyl, naphthyl, phenyl, tetrahydronaphthyland cyclopropylphenyl. The aryl group can be attached to the parentstructure through any substitutable carbon atom in the group.

“Arylalkyl” is a C₁-C₅ alkyl group attached to 1 to 2 aryl groups andlinked to the parent structure through the alkyl moiety. Examplesinclude, but are not limited to, —(CH₂)_(n)Ph with n=1-5, —CH(CH₃)Ph,—CH(Ph)₂.

“Aryloxy” is an aryl group attached to the parent structure by oxygen.

“Cycloalkyl” means a monocyclic ring system composed of 3 to 7 carbons.

“Halo” includes fluoro, chloro, bromo, and iodo.

“Haloalkyl” and “haloalkoxy” include all halogenated isomers frommonohalo to perhalo.

“Heteroaryl” is a subset of heterocyclic group as defined below and iscomprised of 1-3 rings where at least one or a combination of which isaromatic and that the aromatic group contains at least one atom chosenfrom a group of oxygen, nitrogen or sulfur.

“Heterocyclyl or heterocyclic” means a cyclic group of 1-3 ringscomprised of carbon and at least one other atom selected independentlyfrom oxygen, nitrogen and sulfur. The rings could be bridged, fusedand/or bonded, through a direct or spiro attachment, with the option tohave one or a combination thereof be aromatic. Examples include, but arenot limited to, azaindole, azaindoline, azetidine, benzimidazole,bezodioxolyl, benzoisothiazole, benzothiazole, benzothiadiazole,benzothiophene, benzoxazole, carbazole, chroman, dihalobezodioxolyl,dihydrobenzofuran, dihydrobenzo[1,4]oxazine,1,3-dihydrobenzo[c]thiophene 2,2-dioxide, 2,3-dihydrobenzo[d]isothiazole1,1-dioxide, 3,4-dihydro-2H-pyrido[3,2-b][1,4]oxazine,2,3-dihydro-1H-pyrrolo[3,4-c]pyridine and its regioisomeric variants,6,7-dihydro-5H-pyrrolo[2,3-b]pyrazine and its regioisomeric variants,furanylphenyl, imidazole, imidazo[1,2-a]pyridine, indazole, indole,indoline, isoquinoline, isoquinolinone, isothiazolidine 1,1-dioxide,morpholine, 2-oxa-5-azabicyclo[2.2.1]heptane, oxadiazole-phenyl,oxazole, phenylaztidine, phenylindazole, phenylpiperidine,phenylpiperizine, phenyloxazole, phenylpyrrolidine, piperidine,pyridine, pyridinylphenyl, pyridinylpyrrolidine, pyrimidine,pyrimidinylphenyl, pyrrazole-phenyl, pyrrolidine, pyrrolidin-2-one,1H-pyrazolo[4,3-c]pyridine and its regioisomeric variants, pyrrole,5H-pyrrolo[2,3-b]pyrazine, 7H-pyrrolo[2,3-d]pyrimidine and itsregioisomeric variants, quinazoline, quinoline, quinoxaline,tetrahydroisoquinoline, 1,2,3,4-tetrahydro-1,8-naphthyridine,tetrahydroquinoline, 4,5,6,7-tetrahydrothieno[3,2-c]pyridine,1,2,5-thiadiazolidine 1,1-dioxide, thiophene, thiophenylphenyl,triazole, or triazolone. Unless otherwise specifically set forth, theheterocyclic group can be attached to the parent structure through anysuitable atom in the group that results in a stable compound.

It is understood that a subset of the noted heterocyclic examplesencompass regioisomers. For instance, “azaindole” refers to any of thefollowing regioisomers: 1H-pyrrolo[2,3-b]pyridine,1H-pyrrolo[2,3-c]pyridine, 1H-pyrrolo[3,2-c]pyridine, and1H-pyrrolo[3,2-b]pyridine. In addition the “regioisomer variants”notation as in, for example, “5H-pyrrolo[2,3-b]pyrazine and itsregioisomeric variants” would also encompass7H-pyrrolo[2,3-d]pyrimidine, 7H-pyrrolo[2,3-c]pyridazine,1H-pyrrolo[2,3-d]pyridazine, 5H-pyrrolo[3,2-c]pyridazine, and5H-pyrrolo[3,2-d]pyrimidine. Similarly,6,7-dihydro-5H-pyrrolo[2,3-b]pyrazine and its regioisomeric variantswould encompass 6,7-dihydro-5H-pyrrolo[2,3-d]pyrimidine and6,7-dihydro-5H-pyrrolo[2,3-c]pyridazine. It is also understood that thelack of “regioisomeric variants” notation does not in any way restrictthe claim scope to the noted example only.

“Heterocyclylalkyl” is a heterocyclyl moiety attached to the parentstructure through C₁-C₅ alkyl group. Examples include, but are notlimited to, —(CH₂)_(n)—R^(Z) or —CH(CH₃)—(R^(Z)) where n=1-5 and thatR^(Z) is chosen from benzimidazole, imidazole, indazole, isooxazole,phenyl-pyrazole, pyridine, quinoline, thiazole, triazole, triazolone,oxadiazole.

Terms with a hydrocarbon moiety (e.g. alkoxy) include straight andbranched isomers for the hydrocarbon portion with the indicated numberof carbon atoms.

Bonding and positional bonding relationships are those that are stableas understood by practitioners of organic chemistry.

Parenthetic and multiparenthetic terms are intended to clarify bondingrelationships to those skilled in the art. For example, a term such as((R)alkyl) means an alkyl substituent further substituted with thesubstituent R.

Substituents which are illustrated by chemical drawing to bond atvariable positions on a multiple ring system (for example a bicyclicring system) are intended to bond to the ring where they are drawn toappend. Parenthetic and multiparenthetic terms are intended to clarifybonding relationships to those skilled in the art. For example, a termsuch as ((R)alkyl) means an alkyl substituent further substituted withthe substituent R.

“Combination,” “coadministration,” “concurrent” and similar termsreferring to the administration of a compound of Formula I with at leastone anti-HIV agent mean that the components are part of a combinationantiretroviral therapy or highly active antiretroviral therapy (“HAART”)as understood by practitioners in the field of AIDS and HIV infection.

“Therapeutically effective” means the amount of agent required toprovide a benefit to a patient as understood by practitioners in thefield of AIDS and HIV infection. In general, the goals of treatment aresuppression of viral load, restoration and preservation of immunologicfunction, improved quality of life, and reduction of HIV-relatedmorbidity and mortality.

“Patient” means a person infected with the HIV virus.

“Treatment,” “therapy,” “regimen,” “HIV infection,” “ARC,” “AIDS” andrelated terms are used as understood by practitioners in the field ofAIDS and HIV infection.

Those terms not specifically set forth herein shall have the meaningwhich is commonly understood and accepted in the art.

The invention includes all pharmaceutically acceptable salt forms of thecompounds. Pharmaceutically acceptable salts are those in which thecounter ions do not contribute significantly to the physiologicalactivity or toxicity of the compounds and as such function aspharmacological equivalents. These salts can be made according to commonorganic techniques employing commercially available reagents. Someanionic salt forms include acetate, acistrate, besylate, bromide,chloride, citrate, fumarate, glucouronate, hydrobromide, hydrochloride,hydroiodide, iodide, lactate, maleate, mesylate, nitrate, pamoate,phosphate, succinate, sulfate, tartrate, tosylate, and xinofoate. Somecationic salt forms include ammonium, aluminum, benzathine, bismuth,calcium, choline, diethylamine, diethanolamine, lithium, magnesium,meglumine, 4-phenylcyclohexylamine, piperazine, potassium, sodium,tromethamine, and zinc.

Some of the compounds of the invention exist in stereoisomeric forms.The invention includes all stereoisomeric forms of the compoundsincluding enantiomers and diastereromers. Methods of making andseparating stereoisomers are known in the art. The invention includesall tautomeric forms of the compounds. The invention includesatropisomers and rotational isomers.

The invention is intended to include all isotopes of atoms occurring inthe present compounds. Isotopes include those atoms having the sameatomic number but different mass numbers. By way of general example andwithout limitation, isotopes of hydrogen include deuterium and tritium.Isotopes of carbon include ¹³C and ¹⁴C. Isotopically-labeled compoundsof the invention can generally be prepared by conventional techniquesknown to those skilled in the art or by processes analogous to thosedescribed herein, using an appropriate isotopically-labeled reagent inplace of the non-labeled reagent otherwise employed. Such compounds mayhave a variety of potential uses, for example as standards and reagentsin determining biological activity. In the case of stable isotopes, suchcompounds may have the potential to favorably modify biological,pharmacological, or pharmacokinetic properties.

In an aspect of the invention, there is provided a compound of FormulaI:

-   wherein:-   R¹ is selected from hydrogen, alkyl, or cycloalkyl;-   R² is tetrahydroisoquinolinyl substituted with 1 R⁶ substituent and    also with 0-3 halo or alkyl substituents;-   R³ is selected from azetidinyl, pyrrolidinyl, piperidinyl,    piperazinyl, morpholinyl, homopiperidinyl, homopiperazinyl, or    homomorpholinyl, and is substituted with 0-3 substituents selected    from cyano, halo, alkyl, haloalkyl, alkoxy, and haloalkoxy;-   R⁴ is selected from alkyl or haloalkyl;-   R⁵ is alkyl; and-   R⁶ is selected from phenanthrolinyl, phenanthridinyl,    pyridofuropyrimidinyl, imidazothiazolopyridinyl,    benzofuropyrimidinyl, benzothienopyrimidinyl, or pyrimidoindolyl,    and is substituted with 0-3 substituents selected from cyano, halo,    alkyl, haloalkyl, alkoxy, thioalkyl, and haloalkoxy;-   or a pharmaceutically acceptable salt thereof.

In an aspect of the invention, R² is tetrahydroisoquinolin-6-ylsubstituted with 1 R⁶ substituent and also with 0-3 halo or alkylsubstituents.

In an aspect of the invention, R³ is piperidinyl substituted with 0-3substituents selected from cyano, halo, alkyl, haloalkyl, alkoxy, andhaloalkoxy.

In an aspect of the invention, there is provided a compound of FormulaI:

-   wherein:-   R¹ is selected from hydrogen, alkyl, or cycloalkyl;-   R² is tetrahydroisoquinolin-6-yl substituted with 1 R⁶ substituent    and also with 0-3 halo or alkyl substituents;-   R³ is selected from azetidinyl, pyrrolidinyl, piperidinyl,    piperazinyl, morpholinyl, homopiperidinyl, homopiperazinyl, or    homomorpholinyl, and is substituted with 0-3 substituents selected    from cyano, halo, alkyl, haloalkyl, alkoxy, and haloalkoxy;-   R⁴ is selected from alkyl or haloalkyl;-   R⁵ is alkyl; and-   R⁶ is selected from phenanthrolinyl, phenanthridinyl,    pyridofuropyrimidinyl, imidazothiazolopyridinyl,    benzofuropyrimidinyl, benzothienopyrimidinyl, or pyrimidoindolyl,    and is substituted with 0-3 substituents selected from cyano, halo,    alkyl, haloalkyl, alkoxy, thioalkyl, and haloalkoxy;-   or a pharmaceutically acceptable salt thereof.

In an aspect of the invention, there is provided a compound of FormulaI:

-   wherein:-   R¹ is selected from hydrogen, alkyl, or cycloalkyl;-   R² is tetrahydroisoquinolinyl substituted with 1 R⁶ substituent and    also with 0-3 halo or alkyl substituents;-   R³ is piperidinyl substituted with 0-3 substituents selected from    cyano, halo, alkyl, haloalkyl, alkoxy, and haloalkoxy;-   R⁴ is selected from alkyl or haloalkyl;-   R⁵ is alkyl; and-   R⁶ is selected from phenanthrolinyl, phenanthridinyl,    pyridofuropyrimidinyl, imidazothiazolopyridinyl,    benzofuropyrimidinyl, benzothienopyrimidinyl, or pyrimidoindolyl,    and is substituted with 0-3 substituents selected from cyano, halo,    alkyl, haloalkyl, alkoxy, thioalkyl, and haloalkoxy;-   or a pharmaceutically acceptable salt thereof.

For a particular compound of Formula I, the scope of any instance of avariable substituent, including R¹, R², R³, R⁴, R⁵ and R⁶ can be usedindependently with the scope of any other instance of a variablesubstituent. As such, the invention includes combinations of thedifferent aspects.

In an aspect of the invention, there is provided a composition usefulfor treating HIV infection comprising a therapeutic amount of a compoundof Formula I and a pharmaceutically acceptable carrier. In an aspect ofthe invention, the composition further comprises a therapeuticallyeffective amount at least one other agent used for treatment of AIDS orHIV infection selected from nucleoside HIV reverse transcriptaseinhibitors, non-nucleoside HIV reverse transcriptase inhibitors, HIVprotease inhibitors, HIV fusion inhibitors, HIV attachment inhibitors,CCR5 inhibitors, CXCR4 inhibitors, HIV budding or maturation inhibitors,and HIV integrase inhibitors, and a pharmaceutically acceptable carrier.In an aspect of the invention, the other agent is dolutegravir.

In an aspect of the invention, there is provided a method for treatingHIV infection comprising administering a therapeutically effectiveamount of a compound of Formula I, or a pharmaceutically acceptable saltthereof, to a patient in need thereof. In an aspect of the invention,the method further comprises administering a therapeutically effectiveamount of at least one other agent used for treatment of AIDS or HIVinfection selected from nucleoside HIV reverse transcriptase inhibitors,non-nucleoside HIV reverse transcriptase inhibitors, HIV proteaseinhibitors, HIV fusion inhibitors, HIV attachment inhibitors, CCR5inhibitors, CXCR4 inhibitors, HIV budding or maturation inhibitors, andHIV integrase inhibitors. In an aspect of the invention, the other agentis dolutegravir. In an aspect of the invention, the other agent isadministered to the patient prior to, simultaneously with, orsubsequently to the compound of Formula I.

Preferred compounds in accordance with the present invention include thefollowing:

-   (S)-2-(5-(2-(benzofuro[3,2-d]pyrimidin-4-yl)-1,2,3,4-tetrahydroisoquinolin-6-yl)-4-(4,4-dimethylpiperidin-1-yl)-2,6-dimethylpyridin-3-yl)-2-(tert-butoxy)acetic    acid;-   (S)-2-(5-(2-(1,10-phenanthrolin-2-yl)-1,2,3,4-tetrahydroisoquinolin-6-yl)-4-(4,4-dimethylpiperidin-1-yl)-2,6-dimethylpyridin-3-yl)-2-(tert-butoxy)acetic    acid;-   (S)-2-(tert-butoxy)-2-(4-(4,4-dimethylpiperidin-1-yl)-2,6-dimethyl-5-(2-(phenanthridin-6-yl)-1,2,3,4-tetrahydroisoquinolin-6-yl)pyridin-3-yl)acetic    acid;-   (S)-2-(tert-butoxy)-2-(5-(2-(4-chloro-7-methyl-9H-pyrimido[4,5-b]indol-2-yl)-1,2,3,4-tetrahydroisoquinolin-6-yl)-4-(4,4-dimethylpiperidin-1-yl)-2,6-dimethylpyridin-3-yl)acetic    acid;-   (S)-2-(tert-butoxy)-2-(4-(4,4-dimethylpiperidin-1-yl)-5-(2-(8-fluorobenzofuro[3,2-d]pyrimidin-4-yl)-1,2,3,4-tetrahydroisoquinolin-6-yl)-2,6-dimethylpyridin-3-yl)acetic    acid;-   (S)-2-(tert-butoxy)-2-(4-(4,4-dimethylpiperidin-1-yl)-2,6-dimethyl-5-(2-(8-methyl-5H-pyrimido[5,4-b]indol-4-yl)-1,2,3,4-tetrahydroisoquinolin-6-yl)pyridin-3-yl)acetic    acid;-   (S)-2-(tert-butoxy)-2-(4-(4,4-dimethylpiperidin-1-yl)-5-(2-(9-fluorobenzofuro[3,2-d]pyrimidin-4-yl)-1,2,3,4-tetrahydroisoquinolin-6-yl)-2,6-dimethylpyridin-3-yl)acetic    acid;-   (S)-2-(tert-butoxy)-2-(4-(4,4-dimethylpiperidin-1-yl)-5-(2-(5-ethyl-8-methyl-5H-pyrimido[5,4-b]indol-4-yl)-1,2,3,4-tetrahydroisoquinolin-6-yl)-2,6-dimethylpyridin-3-yl)acetic    acid;-   (S)-2-(tert-butoxy)-2-(4-(4,4-dimethylpiperidin-1-yl)-2,6-dimethyl-5-(2-(8-methyl-2-(methylthio)-8H-imidazo[4,5-d]thiazolo[5,4-b]pyridin-5-yl)-1,2,3,4-tetrahydroisoquinolin-6-yl)pyridin-3-yl)acetic    acid;-   (S)-2-(5-(2-(5H-pyrimido[5,4-b]indol-4-yl)-1,2,3,4-tetrahydroisoquinolin-6-yl)-4-(4,4-dimethylpiperidin-1-yl)-2,6-dimethylpyridin-3-yl)-2-(tert-butoxy)acetic    acid;-   (S)-2-(5-(2-(benzo[4,5]thieno[2,3-d]pyrimidin-4-yl)-1,2,3,4-tetrahydroisoquinolin-6-yl)-4-(4,4-dimethylpiperidin-1-yl)-2,6-dimethylpyridin-3-yl)-2-(tert-butoxy)acetic    acid;-   (S)-2-(5-(2-(9H-pyrimido[4,5-b]indol-4-yl)-1,2,3,4-tetrahydroisoquinolin-6-yl)-4-(4,4-dimethylpiperidin-1-yl)-2,6-dimethylpyridin-3-yl)-2-(tert-butoxy)acetic    acid;-   (S)-2-(5-(2-(benzo[4,5]thieno[3,2-d]pyrimidin-4-yl)-1,2,3,4-tetrahydroisoquinolin-6-yl)-4-(4,4-dimethylpiperidin-1-yl)-2,6-dimethylpyridin-3-yl)-2-(tert-butoxy)acetic    acid;-   (S)-2-(tert-butoxy)-2-(4-(4,4-dimethylpiperidin-1-yl)-2,6-dimethyl-5-(2-(pyrido[3′,2′:4,5]furo[3,2-d]pyrimidin-4-yl)-1,2,3,4-tetrahydroisoquinolin-6-yl)pyridin-3-yl)acetic    acid; and-   pharmaceutically acceptable salts thereof.

The compounds of the invention herein described may typically beadministered as pharmaceutical compositions. These compositions arecomprised of a therapeutically effective amount of a compound of FormulaI or its pharmaceutically acceptable salt, and a pharmaceuticallyacceptable carrier and may contain conventional excipients and/ordiluents. A therapeutically effective amount is that which is needed toprovide a meaningful patient benefit. Pharmaceutically acceptablecarriers are those conventionally known carriers having acceptablesafety profiles. Compositions encompass all common solid and liquidforms, including capsules, tablets, lozenges, and powders, as well asliquid suspensions, syrups, elixirs, and solutions. Compositions aremade using available formulation techniques, and excipients (such asbinding and wetting agents) and vehicles (such as water and alcohols)which are generally used for compositions. See, for example, Remington'sPharmaceutical Sciences, 17th edition, Mack Publishing Company, Easton,Pa. (1985).

Solid compositions which are normally formulated in dosage units andcompositions providing from about 1 to 1000 milligram (“mg”) of theactive ingredient per dose are typical. Some examples of dosages are 1mg, 10 mg, 100 mg, 250 mg, 500 mg, and 1000 mg. Generally, otherantiretroviral agents will be present in a unit range similar to agentsof that class used clinically. Typically, this is about 0.25-1000mg/unit.

Liquid compositions are usually in dosage unit ranges. Generally, theliquid composition will be in a unit dosage range of about 1-100milligram per milliliter (“mg/mL”). Some examples of dosages are 1mg/mL, 10 mg/mL, 25 mg/mL, 50 mg/mL, and 100 mg/mL. Generally, otherantiretroviral agents will be present in a unit range similar to agentsof that class used clinically. Typically, this is about 1-100 mg/mL.

The invention encompasses all conventional modes of administration; oraland parenteral methods are preferred. Generally, the dosing regimen willbe similar to other antiretroviral agents used clinically. Typically,the daily dose will be about 1-100 milligram per kilogram (“mg/kg”) bodyweight daily. Generally, more compound is required orally and lessparenterally. The specific dosing regimen, however, will be determinedby a physician using sound medical judgment.

The compounds of this invention desirably have activity against HIV.Accordingly, another aspect of the invention is a method for treatingHIV infection in a human patient comprising administering atherapeutically effective amount of a compound of Formula I, or apharmaceutically acceptable salt thereof, with a pharmaceuticallyacceptable carrier, excipient and/or diluent.

The invention also encompasses methods where the compound is given incombination therapy. That is, the compound can be used in conjunctionwith, but separately from, other agents useful in treating AIDS and HIVinfection. The compound can also be used in combination therapy whereinthe compound and one or more of the other agents are physically togetherin a fixed-dose combination (FDC). Some of these agents include HIVattachment inhibitors, CCR5 inhibitors, CXCR4 inhibitors, HIV cellfusion inhibitors, HIV integrase inhibitors, HIV nucleoside reversetranscriptase inhibitors, HIV non-nucleoside reverse transcriptaseinhibitors, HIV protease inhibitors, budding and maturation inhibitors,HIV capsid inhibitors, anti-infectives, and immunomodulators, such as,for example, PD-1 inhibitors, PD-L1 inhibitors, antibodies, and thelike. In these combination methods, the compound of Formula I willgenerally be given in a daily dose of about 1-100 mg/kg body weightdaily in conjunction with other agents. The other agents generally willbe given in the amounts used therapeutically. The specific dosingregimen, however, will be determined by a physician using sound medicaljudgment.

Examples of nucleoside HIV reverse transcriptase inhibitors includeabacavir, didanosine, emtricitabine, lamivudine, stavudine, tenofovir,zalcitabine, and zidovudine.

Examples of non-nucleoside HIV reverse transcriptase inhibitors includedelavirdine, efavirenz, etrivirine, nevirapine, and rilpivirine.

Examples of HIV protease inhibitors include amprenavir, atazanavir,darunavir, fosamprenavir, indinavir, lopinavir, nelfinavir, ritonavir,saquinavir and, tipranavir.

An example of an HIV fusion inhibitor is enfuvirtide or T-1249.

An example of an HIV entry inhibitor is maraviroc.

Examples of HIV integrase inhibitors include dolutegravir, elvitegravir,or raltegravir.

An example of an HIV attachment inhibitor is fostemsavir.

An example of an HIV maturation inhibitor is BMS-955176, having thefollowing structure:

Thus, as set forth above, contemplated herein are combinations of thecompounds of Formula I, together with one or more agents useful in thetreatment of AIDS. For example, the compounds of the invention may beeffectively administered, whether at periods of pre-exposure and/orpost-exposure, in combination with effective amounts of the AIDSantivirals, immunomodulators, anti-infectives, or vaccines, such asthose in the following non-limiting table:

ANTIVIRALS Drug Name Manufacturer Indication Rilpivirine Tibotec HIVinfection, AIDS, ARC (non-nucleoside reverse transcriptase inhibitor)COMPLERA ® Gilead HIV infection, AIDS, ARC; combination withemtricitabine, rilpivirine, and tenofovir disoproxil fumarate 097Hoechst/Bayer HIV infection, AIDS, ARC (non-nucleoside reversetranscriptase (RT) inhibitor) Amprenavir Glaxo Wellcome HIV infection,141 W94 AIDS, ARC GW 141 (protease inhibitor) Abacavir (1592U89) GlaxoWellcome HIV infection, GW 1592 AIDS, ARC (RT inhibitor) AcemannanCarrington Labs ARC (Irving, TX) Acyclovir Burroughs Wellcome HIVinfection, AIDS, ARC AD-439 Tanox Biosystems HIV infection, AIDS, ARCAD-519 Tanox Biosystems HIV infection, AIDS, ARC Adefovir dipivoxilGilead Sciences HIV infection AL-721 Ethigen ARC, PGL (Los Angeles, CA)HIV positive, AIDS Alpha Interferon Glaxo Wellcome Kaposi's sarcoma, HIVin combination w/Retrovir Ansamycin Adria Laboratories ARC LM 427(Dublin, OH) Erbamont (Stamford, CT) Antibody which Advanced BiotherapyAIDS, ARC Neutralizes pH Concepts Labile alpha aberrant (Rockville, MD)Interferon AR177 Aronex Pharm HIV infection, AIDS, ARC Beta-fluoro-ddANat'l Cancer Institute AIDS-associated diseases CI-1012 Warner-LambertHIV-1 infection Cidofovir Gilead Science CMV retinitis, herpes,papillomavirus Curdlan sulfate AJI Pharma USA HIV infectionCytomegalovirus MedImmune CMV retinitis Immune globin Cytovene SyntexSight threatening Ganciclovir CMV peripheral CMV retinitis DarunavirTibotec-J & J HIV infection, AIDS, ARC (protease inhibitor) DelaviridinePharmacia-Upjohn HIV infection, AIDS, ARC (RT inhibitor) Dextran SulfateUeno Fine Chem. AIDS, ARC, HIV Ind. Ltd. (Osaka, positive Japan)asymptomatic ddC Hoffman-La Roche HIV infection, AIDS, DideoxycytidineARC ddI Bristol-Myers Squibb HIV infection, AIDS, Dideoxyinosine ARC;combination with AZT/d4T DMP-450 AVID HIV infection, (Camden, NJ) AIDS,ARC (protease inhibitor) Efavirenz Bristol Myers Squibb HIV infection,(DMP 266, SUSTIVA ®) AIDS, ARC (−)6-Chloro-4-(S)- (non-nucleoside RTcyclopropylethynyl- inhibitor) 4(S)-trifluoro- methyl-1,4-dihydro-2H-3,1-benzoxazin- 2-one, STOCRINE EL10 Elan Corp, PLC HIV infection(Gainesville, GA) Etravirine Tibotec/J & J HIV infection, AIDS, ARC(non-nucleoside reverse transcriptase inhibitor) Famciclovir Smith Klineherpes zoster, herpes simplex GS 840 Gilead HIV infection, AIDS, ARC(reverse transcriptase inhibitor) HBY097 Hoechst Marion HIV infection,Roussel AIDS, ARC (non-nucleoside reverse transcriptase inhibitor)Hypericin VIMRx Pharm. HIV infection, AIDS, ARC Recombinant Human TritonBiosciences AIDS, Kaposi's Interferon Beta (Almeda, CA) sarcoma, ARCInterferon alfa-n3 Interferon Sciences ARC, AIDS Indinavir Merck HIVinfection, AIDS, ARC, asymptomatic HIV positive, also in combinationwith AZT/ddI/ddC ISIS 2922 ISIS Pharmaceuticals CMV retinitis KNI-272Nat'l Cancer Institute HIV-assoc. diseases Lamivudine, 3TC GlaxoWellcome HIV infection, AIDS, ARC (reverse transcriptase inhibitor);also with AZT Lobucavir Bristol-Myers Squibb CMV infection NelfinavirAgouron HIV infection, Pharmaceuticals AIDS, ARC (protease inhibitor)Nevirapine Boeheringer HIV infection, Ingleheim AIDS, ARC (RT inhibitor)Novapren Novaferon Labs, Inc. HIV inhibitor (Akron, OH) Peptide TPeninsula Labs AIDS Octapeptide (Belmont, CA) Sequence Trisodium AstraPharm. CMV retinitis, HIV Phosphonoformate Products, Inc. infection,other CMV infections PNU-140690 Pharmacia Upjohn HIV infection, AIDS,ARC (protease inhibitor) Probucol Vyrex HIV infection, AIDS RBC-CD4Sheffield Med. HIV infection, Tech (Houston, TX) AIDS, ARC RitonavirAbbott HIV infection, AIDS, ARC (protease inhibitor) SaquinavirHoffmann- HIV infection, LaRoche AIDS, ARC (protease inhibitor)Stavudine; d4T Bristol-Myers Squibb HIV infection, AIDS, Didehydrodeoxy-ARC Thymidine Tipranavir Boehringer Ingelheim HIV infection, AIDS, ARC(protease inhibitor) Valaciclovir Glaxo Wellcome Genital HSV & CMVInfections Virazole Viratek/ICN asymptomatic HIV Ribavirin (Costa Mesa,CA) positive, LAS, ARC VX-478 Vertex HIV infection, AIDS, ARCZalcitabine Hoffmann-LaRoche HIV infection, AIDS, ARC, with AZTZidovudine; AZT Glaxo Wellcome HIV infection, AIDS, ARC, Kaposi'ssarcoma, in combination with other therapies Tenofovir disoproxil,Gilead HIV infection, fumarate salt (VIREAD ®) AIDS, (reversetranscriptase inhibitor) EMTRIVA ® Gilead HIV infection, (Emtricitabine)(FTC) AIDS, (reverse transcriptase inhibitor) COMBIVIR ® GSK HIVinfection, AIDS, (reverse transcriptase inhibitor) Abacavir succinateGSK HIV infection, (or ZIAGEN ®) AIDS, (reverse transcriptase inhibitor)REYATAZ ® Bristol-Myers Squibb HIV infection (or atazanavir) AIDs,protease inhibitor FUZEON ® Roche/Trimeris HIV infection (Enfuvirtide orT-20) AIDs, viral Fusion inhibitor LEXIVA ® GSK/Vertex HIV infection (orFosamprenavir calcium) AIDs, viral protease inhibitor SELZENTRY ™ PfizerHIV infection Maraviroc; (UK 427857) AIDs, (CCR5 antagonist, indevelopment) TRIZIVIR ® GSK HIV infection AIDs, (three drug combination)Sch-417690 (vicriviroc) Schering-Plough HIV infection AIDs, (CCR5antagonist, in development) TAK-652 Takeda HIV infection AIDs, (CCR5antagonist, in development) GSK 873140 GSK/ONO HIV infection (ONO-4128)AIDs, (CCR5 antagonist, in development) Integrase Inhibitor Merck HIVinfection MK-0518 AIDs Raltegravir TRUVADA ® Gilead Combination ofTenofovir disoproxil fumarate salt (VIREAD ®) and EMTRIVA ®(Emtricitabine) Integrase Inhibitor Gilead/Japan Tobacco HIV InfectionGS917/JTK-303 AIDs Elvitegravir in development Triple drug combinationGilead/Bristol-Myers Squibb Combination of Tenofovir ATRIPLA ®disoproxil fumarate salt (VIREAD ®), EMTRIVA ® (Emtricitabine), andSUSTIVA ® (Efavirenz) FESTINAVIR ® Oncolys BioPharma HIV infection AIDsin development CMX-157 Chimerix HIV infection Lipid conjugate of AIDsnucleotide tenofovir GSK1349572 GSK HIV infection Integrase inhibitorAIDs TIVICAY ® dolutegravir

IMMUNOMODULATORS Drug Name Manufacturer Indication AS-101 Wyeth-AyerstAIDS Bropirimine Pharmacia Upjohn Advanced AIDS Acemannan CarringtonLabs, Inc. AIDS, ARC (Irving, TX) CL246,738 Wyeth AIDS, Kaposi's LederleLabs sarcoma FP-21399 Fuki ImmunoPharm Blocks HIV fusion with CD4+ cellsGamma Interferon Genentech ARC, in combination w/TNF (tumor necrosisfactor) Granulocyte Genetics Institute AIDS Macrophage Colony SandozStimulating Factor Granulocyte Hoechst-Roussel AIDS Macrophage ColonyImmunex Stimulating Factor Granulocyte Schering-Plough AIDS, MacrophageColony combination Stimulating Factor w/AZT HIV Core Particle RorerSeropositive HIV Immunostimulant IL-2 Cetus AIDS, in combinationInterleukin-2 w/AZT IL-2 Hoffman-LaRoche AIDS, ARC, HIV, inInterleukin-2 Immunex combination w/AZT IL-2 Chiron AIDS, increase inInterleukin-2 CD4 cell counts (aldeslukin) Immune Globulin CutterBiological Pediatric AIDS, in Intravenous (Berkeley, CA) combinationw/AZT (human) IMREG-1 Imreg AIDS, Kaposi's (New Orleans, LA) sarcoma,ARC, PGL IMREG-2 Imreg AIDS, Kaposi's (New Orleans, LA) sarcoma, ARC,PGL Imuthiol Diethyl Merieux Institute AIDS, ARC Dithio CarbamateAlpha-2 Schering Plough Kaposi's sarcoma Interferon w/AZT, AIDSMethionine- TNI Pharmaceutical AIDS, ARC Enkephalin (Chicago, IL) MTP-PECiba-Geigy Corp. Kaposi's sarcoma Muramyl-Tripeptide Granulocyte AmgenAIDS, in combination Colony Stimulating w/AZT Factor Remune ImmuneResponse Immunotherapeutic Corp. rCD4 Genentech AIDS, ARC RecombinantSoluble Human CD4 rCD4-IgG AIDS, ARC hybrids Recombinant Biogen AIDS,ARC Soluble Human CD4 Interferon Hoffman-La Roche Kaposi's sarcoma Alfa2a AIDS, ARC, in combination w/AZT SK&F106528 Smith Kline HIV infectionSoluble T4 Thymopentin Immunobiology HIV infection Research Institute(Annandale, NJ) Tumor Necrosis Genentech ARC, in combination Factor; TNFw/gamma Interferon

ANTI-INFECTIVES Drug Name Manufacturer Indication Clindamycin withPharmacia Upjohn PCP Primaquine Fluconazole Pfizer Cryptococcalmeningitis, candidiasis Pastille Squibb Corp. Prevention of NystatinPastille oral candidiasis Ornidyl Merrell Dow PCP EflornithinePentamidine LyphoMed PCP treatment Isethionate (IM & IV) (Rosemont, IL)Trimethoprim Antibacterial Trimethoprim/sulfa Antibacterial PiritreximBurroughs Wellcome PCP treatment Pentamidine Fisons Corporation PCPprophylaxis Isethionate for Inhalation Spiramycin Rhone-PoulencCryptosporidial diarrhea Intraconazole- Janssen-Pharm. Histoplasmosis;R51211 cryptococcal meningitis Trimetrexate Warner-Lambert PCPDaunorubicin NeXstar, Sequus Kaposi's sarcoma Recombinant Human OrthoPharm. Corp. Severe anemia Erythropoietin assoc. with AZT therapyRecombinant Human Serono AIDS-related Growth Hormone wasting, cachexiaMegestrol Acetate Bristol-Myers Squibb Treatment of anorexia assoc.W/AIDS Testosterone Alza, Smith Kline AIDS-related wasting Total EnteralNorwich Eaton Diarrhea and Nutrition Pharmaceuticals malabsorptionrelated to AIDS

Methods of Synthesis

The compounds of this invention can be made by various methods known inthe art including those of the following schemes and in the specificembodiments section. The structure numbering and variable numberingshown in the synthetic schemes are distinct from, and should not beconfused with, the structure or variable numbering in the claims or therest of the specification. The variables in the schemes are meant onlyto illustrate how to make some of the compounds of this invention. Thedisclosure is not limited to the foregoing illustrative examples and theexamples should be considered in all respects as illustrative and notrestrictive, reference being made to the appended claims, rather than tothe foregoing examples, and all changes which come within the meaningand range of equivalency of the claims are therefore intended to beembraced.

Abbreviations used in the schemes and examples generally followconventions used in the art. Chemical abbreviations used in thespecification and examples are defined as follows: “KHMDS” for potassiumbis(trimethylsilyl)amide; “DMF” for N,N-dimethylformamide; “HATU” forO-(t-Azabenzotriazol-1-yl)-N,N,N′,N′-tetramethyluroniumhexafluorophosphate, “MeOH” for methanol; “Ar” for aryl; “TFA” fortrifluoroacetic acid, “DMSO” for dimethylsulfoxide; “h” for hours; “rt”for room temperature or retention time (context will dictate); “min” forminutes; “EtOAc” for ethyl acetate; “THF” for tetrahydrofuran; “Et₂O”for diethyl ether; “DMAP” for 4-dimethylaminopyridine; “DCE” for1,2-dichloroethane; “ACN” for acetonitrile; “DME” for1,2-dimethoxyethane; “HOBt” for 1-hydroxybenzotriazole hydrate; and“DIEA” for diisopropylethylamine.

Certain other abbreviations as used herein, are defined as follows: “1×”for once, “2×” for twice, “3×” for thrice, “° C.” for degrees Celsius,“eq” for equivalent or equivalents, “g” for gram or grams, “mg” formilligram or milligrams, “L” for liter or liters, “mL” for milliliter ormilliliters, “μL” for microliter or microliters, “N” for normal, “M” formolar, “mmol” for millimole or millimoles, “atm” for atmosphere, “psi”for pounds per square inch, “conc.” for concentrate, “sat” or “sat'd”for saturated, “MW” for molecular weight, “mp” for melting point, “ee”for enantiomeric excess, “MS” or “Mass Spec” for mass spectrometry,“ESI” for electrospray ionization mass spectroscopy, “HR” for highresolution, “HRMS” for high resolution mass spectrometry, “LCMS” forliquid chromatography mass spectrometry, “HPLC” for high pressure liquidchromatography, “RP HPLC” for reverse phase HPLC, “TLC” or “tlc” forthin layer chromatography, “NMR” for nuclear magnetic resonancespectroscopy, “¹H” for proton, “δ” for delta, “s” for singlet, “d” fordoublet, “t” for triplet, “q” for quartet, “m” for multiplet, “br” forbroad, “Hz” for hertz, and “α”, “β”, “R”, “S”, “E”, and “Z” arestereochemical designations familiar to one skilled in the art.

Some compounds of this invention can be prepared by the methods outlinedin the Scheme I

Some compounds of this invention can be prepared by the methods outlinedin the Scheme II.

The compounds described herein were purified by the methods well knownto those skilled in art by normal phase column chromatography on silicagel column using appropriate solvent system described. Preparative HPLCpurifications mentioned in this experimentation section were carried outgradient elution either on Sunfire Prep C18 ODB column (5 μm; 19 or30×100 mm) or Waters Xbridge C18 column (5 μM; 19×200 or 30×100 mm) orWater Atlantis (5 μm; 19 or 30×100 mm) using the following mobilephases. Mobile phase A: 9:1 H₂O/acetonitrile with 10 mM NH₄OAc andmobile phase B: A: 9:1 acetonitrile/H₂O with 10 mM NH₄OAc; or mobilephase A: 9:1 H₂O/acetonitrile with 0.1% TFA and mobile phase B: A: 9:1acetonitrile/H₂O with 0.1% TFA; or mobile phase A: water/MeOH (9:1) with20 mM NH₄OAc and mobile phase B: 95:5 MeOH/H₂O with 20 mM NH₄OAc ormobile phase A: water/MeOH (9:1) with 0.1% TFA and mobile phase B: 95:5MeOH/H₂O with 0.1% TFA or mobile Phase A: 5:95 acetonitrile:water with10-mM ammonium acetate; Mobile Phase B: 95:5 acetonitrile:water with10-mM ammonium acetate.

All Liquid Chromatography (LC) data were recorded on a Shimadzu LC-10ASor LC-20AS liquid chromotograph using a SPD-10AV or SPD-20A UV-Visdetector and Mass Spectrometry (MS) data were determined with aMicromass Platform for LC in electrospray mode.

Compounds purified by preparative HPLC were diluted in methanol (1.2 mL)and purified using a Shimadzu LC-8A or LC-10A automated preparative HPLCsystem.

3,5-Dibromo-2,6-dimethylpyridin-4-ol

A 3-neck R.B-flask equipped with mechanical stirrer, addition funnel andcondenser is charged with 2,6-dimethylpyridin-4-ol (100 g, 812 mmol),CH₂Cl₂ (1000 mL) and MeOH (120 mL). To the resulting light brown or tansolution was added tert-BuNH2 (176 ml, 1665 mmol), cooled in water bathmaintained between 5-10° C. (ice-water) and added drop wise Br2 (84 ml,1624 mmol) over 70 min. After the addition was complete cold bath wasremoved and stirred for 1.5 h at rt. Then, the light orange slurry wasfiltered and the filter cake was washed with ether (250 mL) and dried toafford 3,5-dibromo-2,6-dimethylpyridin-4-ol, hydrobromide (280.75 g, 776mmol, 96% yield) as white solid which was used in the next step withoutfurther purification. ¹H NMR (500 MHz, DMSO-d₆) δ 12.08 (br. s., 1H),2.41 (s, 6H). LCMS (M+H)=281.9.

Alternative Procedure:

Bromine (72.8 mL, 1.4 mol) was added via addition funnel over 60 min toa mechanically stirred cold (ice-water bath) solution of2,6-dimethylpyridin-4-ol (87 g, 706 mmol) and 4-methylmorpholine (156mL, 1.4 mol) in dichloromethane (1 L) and methanol (100 mL) and thenstirred for 2 h at rt. Additional bromine (˜15 mL) was added based onmonitoring by LCMS. The product was filtered, washed with ether, anddried under vacuum to give 3,5-dibromo-2,6-dimethylpyridin-4-ol 176.8 g(88%).

3,5-Dibromo-4-chloro-2,6-dimethylpyridine

Triethylamine (28.8 mL, 206 mmol) was added to a nitrogen purgedsolution of 3,5-dibromo-2,6-dimethylpyridin-4-ol (58 g, 206 mmol) andphosphorous oxychloride (57.7 mL, 619 mmol) in chloroform (450 mL) andstirred for 1 h at rt, then 3 h at 80° C. The reaction was removed fromheating and immediately concentrated under house vacuum; then under highvacuum. The appearance was a cream colored solid, which was azeotropedwith toluene (2×100 mL); treated with ice (200 g) for 10 min andcarefully neutralized with NaHCO₃ (powder), and 1N NaOH solution, andextracted with DCM (2×400 mL). The combined organic layers were dried(MgSO₄), concentrated, and a beige solid was obtained that was washedwith hexanes and dried under high vacuum to give3,5-dibromo-4-chloro-2,6-dimethyl-pyridine 52.74 g (85.1%).Concentration of the hexanes gave 3.5 g of less pure product. ¹H NMR(500 MHz, CDCl₃) δ 2.59 (s, 6H). LCMS (M+H)=300.0.

Ethyl 2-(5-bromo-4-chloro-2,6-dimethylpyridin-3-yl)-2-oxoacetate

To a stirred mixture of 3,5-dibromo-4-chloro-2,6-dimethylpyridine (14.94g, 49.9 mmol) and Cu(I)Br Me2S (0.513 g, 2.495 mmol) in THF (50 mL) wasadded drop wise 2M iPrMgCl/THF (26.2 ml, 52.4 mmol) at −30° C. over 5min. Then, the resulting slurry was warmed to −10° C. over 30 min andstirred for 30 min. The homogeneous brown reaction mixture was rapidlytransferred via cannula to a solution of ethyl 2-chloro-2-oxoacetate(6.14 ml, 54.9 mmol, degassed for 5 min by bubbling N2 through thesolution) in THF (50 mL) maintained at −30° C. The resulting reactionmixture was stirred (1.5 h) while warming to 0° C. Then, taken up in toEt₂O (200 mL), washed with 1:1 sat Na₂CO₃/1M NH₄Cl (3×50 mL), dried(MgSO₄), filtered and concentrated to give brown viscous oil. Flashchromatography using 2.5, 5 and 7.5% EtOAc/Hex afforded ethyl2-(5-bromo-4-chloro-2,6-dimethylpyridin-3-yl)-2-oxoacetate (14.37 g,44.8 mmol, 90% yield) as white solid. ¹H NMR (400 MHz, CDCl₃) δ 4.42 (q,J=7.0 Hz, 2H), 2.76 (s, 3H), 2.46 (s, 3H), 1.41 (t, J=7.2 Hz, 3H). LCMS(M+H)=322.1.

Ethyl2-(5-bromo-4-(4,4-dimethylpiperidin-1-yl)-2,6-dimethylpyridin-3-yl)-2-oxoacetate

To a solution of 4,4-dimethylpiperidine (1.245 g, 11.00 mmol) and DIEA(3.49 ml, 20.00 mmol) in anhydrous CH₃CN (40 mL) was added ethyl2-(5-bromo-4-chloro-2,6-dimethylpyridin-3-yl)-2-oxoacetate (3.21 g, 10mmol) at rt. The resulting mixture was placed in a pre-heated oil bath(80° C.). After 22 h, the reaction mixture was concentrated and theresidue was purified by flash chromatography using 1-lit each 2.5, 5,7.5 and 10% EtOAc/Hex to afford ethyl2-(5-bromo-4-(4,4-dimethylpiperidin-1-yl)-2,6-dimethylpyridin-3-yl)-2-oxoacetate(2.846 g, 7.16 mmol, 71.6% yield) as yellow solid. ¹H NMR (500 MHz,CDCl₃) δ 4.37 (q, J=7.1 Hz, 2H), 3.67-2.75 (br.s., 4H), 2.71 (s, 3H),2.44 (s, 3H), 1.42 (t, J=7.1 Hz, 3H), 1.38 (t, J=5.6 Hz, 4H), 1.00 (s,6H). LCMS (M+H)=399.4.

(S)-Ethyl2-(5-bromo-4-(4,4-dimethylpiperidin-1-yl)-2,6-dimethylpyridin-3-yl)-2-hydroxyacetate

To stirred yellow solution of ethyl2-(5-bromo-4-(4,4-dimethylpiperidin-1-yl)-2,6-dimethylpyridin-3-yl)-2-oxoacetate(2.25 g, 5.66 mmol) and(R)-1-methyl-3,3-diphenylhexahydropyrrolo[1,2-c][1,3,2]oxazaborole(0.314 g, 1.133 mmol) in toluene (30 mL) at −35° C. was added drop wise50% catecholborane (1.819 ml, 8.49 mmol) over 10 min. The reactionmixture was slowly warmed to −15° C. over 1 h and then left for 2 h at−15° C. Then, diluted with EtOAc (100 mL), washed with sat Na₂CO₃ (4×25mL) by vigorously stirring and separating aqueous layers. The organiclayer dried (MgSO₄), filtered, concentrated and purified by flashchromatography using 10, 20 and 25% EtOAc/Hex to afford desired(S)-ethyl2-(5-bromo-4-(4,4-dimethylpiperidin-1-yl)-2,6-dimethylpyridin-3-yl)-2-hydroxyacetate(2.2596 g, 5.66 mmol, 100% yield) contaminated with about 10% of(S)-ethyl2-(5-bromo-4-chloro-2,6-dimethylpyridin-3-yl)-2-hydroxyacetate. Used inthe next step without further purification. ¹H NMR (500 MHz, CDCl₃) δ5.71 (d, J=7.3 Hz, 1H), 5.54 (d, J=7.4 Hz, 1H), 4.29 (dq, J=10.8, 7.1Hz, 1H), 4.16 (dq, J=10.8, 7.1 Hz, 1H), 3.94-3.83 (m, 2H), 2.71 (d,J=11.9 Hz, 1H), 2.67 (s, 3H), 2.59 (s, 3H), 2.54 (d, J=12.0 Hz, 1H),1.71 (td, J=12.7, 4.7 Hz, 1H), 1.62 (td, J=13.0, 4.7 Hz, 1H), 1.42 (dd,J=13.1, 2.2 Hz, 1H), 1.37 (dd, J=12.9, 2.4 Hz, 1H), 1.25 (t, J=7.1 Hz,3H), 1.09 (s, 3H), 1.04 (s, 3H). LCMS (M+H)=401.3.

(S)-Ethyl2-(5-bromo-4-(4,4-dimethylpiperidin-1-yl)-2,6-dimethylpyridin-3-yl)-2-(tert-butoxy)acetate

A stirred ice-cold yellow mixture of (S)-ethyl2-(5-bromo-4-(4,4-dimethylpiperidin-1-yl)-2,6-dimethylpyridin-3-yl)-2-hydroxyacetate(2.45 g, 6.14 mmol) and 70% HClO₄ (1.054 ml, 12.27 mmol) in CH₂Cl₂ (100mL) was saturated with isobutylene gas by bubbling through the reactionmixture (10 min). After 2 h, cold bath was removed and the turbidreaction mixture stirred for 22 h at rt. LCMS at this point showed 4:1product to sm. So, saturated with isobutylene (5 min) at rt and stirredfor additional 24 h. Then, neutralized with sat. Na₂CO₃ (30 mL), organiclayer separated and aqueous layer extracted with CH₂Cl₂ (25 mL). Thecombined organic layers dried (MgSO₄), filtered, concentrated andpurified by flash chromatography using 5, 10, 15, 20 and 40% EtOAc/hexto afford (S)-ethyl2-(5-bromo-4-(4,4-dimethylpiperidin-1-yl)-2,6-dimethylpyridin-3-yl)-2-(tert-butoxy)acetate(2.3074 g, 5.07 mmol, 83% yield) as yellow oil: ¹H NMR (500 MHz, CDCl₃)δ 6.19 (br. s., 1H), 4.17-4.24 (m, 1H), 4.08-4.14 (m, 1H), 4.04 (dt,J=2.5, 12.1 Hz, 1H), 3.51 (dt, J=2.5, 12.1 Hz, 1H), 2.85-2.91 (m, 1H),2.64 (s, 3H), 2.57-2.62 (m, 1H), 2.55 (s, 3H), 1.55-1.66 (m, 2H),1.41-1.46 (m, 1H), 1.32-1.37 (m, 1H), 1.21 (s, 9H), 1.20 (t, J=7.2 Hz,2H), 1.08 (s, 3H), 1.03 (s, 3H). LCMS (M+H)=457.4. And (S)-ethyl2-(5-bromo-4-(4,4-dimethylpiperidin-1-yl)-2,6-dimethylpyridin-3-yl)-2-hydroxyacetate(0.3 g, 0.751 mmol, 12.24% yield) as pale yellow paste: LCMS(M+H)=401.3.

The propan-2-ol (38.2 mL, 499 mmol) was added drop wise over 15 min to acold (0° C.), nitrogen purged solution of oxalyl dichloride (101 g, 799mmol) and the reaction was stirred at room temperature for 2.5 h. Then areflux condenser was fitted and a slight vacuum was applied for about 1h until HCl gas was removed (the HCl was trapped in by a sat'd solutionof NaHCO₃). The reflux condenser was removed and the flask was fittedwith a short path distillation head. Excess reagent was removed bydistillation under house vacuum (oil bath heated to 65° C.), and thenthe temperature was raised to between 85-95° C. and the product wasdistilled (NOTE: The 1^(st) fraction of ˜5 mL was discarded) to provideisopropyl 2-chloro-2-oxoacetate 52.62 g (70%).

A solution of 2M isopropyl magnesium chloride (84 mL, 168 mmol) wasadded drop wise over 20 min to a cold (−70° C.), nitrogen purgedsolution of 3,5-dibromo-4-chloro-2,6-dimethylpyridine (48 g, 160 mmol)and copper(I)bromide-dimethyl sulfide complex (1.65 g, 8.02 mmol) in THF(240 mL), which was then allowed to warm to −10° C. over 60 min. Thereaction mixture was transferred via cannula into a 1 L RB-flaskcontaining isopropyl 2-chloro-2-oxoacetate (26.6 g, 176 mmol) in THF(160 mL) maintained at −60° C., and the reaction stirred an additional2.5 h while being allowed to warm to −10° C. The reaction was quenchedupon diluted with a mixture of 10% NH₄Cl solution (80 mL) in ether (320mL). The organic layer was washed with 160 mL of sat'd NaHCO₃/10% NH₄Clsolution (1:1), brine, and dried (Na₂SO₄). The crude product was charged(DCM solution) to a 330 g ISCO silica gel cartridge and gradient eluted(5-20% EtOAc/hexanes) using an Isolera chromatography station gaveisopropyl 2-(5-bromo-4-chloro-2,6-dimethylpyridin-3-yl)-2-oxoacetate40.38 g (76%). ¹H NMR (500 MHz, CDCl₃) δ 5.28-5.21 (m, 1H), 2.77 (s,3H), 2.47 (s, 3H), 1.40 (d, J=6.3 Hz, 6H). LCMS (M+H)=336.04.

To a stirred solution of isopropyl2-(5-bromo-4-chloro-2,6-dimethylpyridin-3-yl)-2-oxoacetate (7.2 g, 21.52mmol) and DIEA (4.13 mL, 23.67 mmol) in anhydrous acetonitrile (15 mL)was added 4,4-dimethylpiperidine (2.68 g, 23.67 mmol) in acetonitrile(15 mL). The resulting solution was placed in a pre-heated oil bath at75° C. After heating (75-78° C.) for 24 h and the temperature was raisedto 85° C. for 24 h. Another portion of DIEA (3.5 mL, 20.04 mmol) and4,4-dimethylpiperidine (0.27 g, 2.4 mmol) in acetonitrile (3 mL) wasadded and hearted at 85° C. for a day. The reaction mixture was dilutedwith ether (100 mL), washed with water (100 mL), brine (50 mL), dried(MgSO₄), filtered, concentrated and purified by ISCO 120 g cartridge(EtOAc/hex: 0 to 20%) to afford isopropyl2-(5-bromo-4-(4,4-dimethylpiperidin-1-yl)-2,6-dimethylpyridin-3-yl)-2-oxoacetate(6.8 g, 16.53 mmol, 77% yield. ¹H NMR (500 MHz, CDCl₃) δ 5.25-5.11 (m,1H), 3.17 (br. s., 4H), 2.71 (s, 3H), 2.41 (s, 3H), 1.42-1.37 (m, 10H),1.00 (s, 6H).). LCMS (M+H)=413.3.

To a yellow solution of isopropyl2-(5-bromo-4-(4,4-dimethylpiperidin-1-yl)-2,6-dimethylpyridin-3-yl)-2-oxoacetate(7.7 g, 18.72 mmol) and(R)-1-methyl-3,3-diphenylhexahydropyrrolo[1,2-c][1,3,2]oxazaborole (7.5mL, 7.50 mmol) in anhydrous toluene (100 mL) was added drop wise 50%catecholborane/toluene (6 mL, 28.0 mmol) over 5 min at −50° C. Then, thereaction mixture was slowly warmed to −30° C. over 1 h and left inrefrigerator (−20° C.) for 3 days. Then, the reaction mixture wasdiluted with EtOAc (100 mL) and 20 mL of 1M Na₂CO₃, and vigorouslystirred for 30 min. Aqueous layer separated and organic layer washedwith sat'd Na₂CO₃ (2×25 mL) by vigorously stirring for 15 each time,then dried (MgSO₄), filtered and concentrated to give crude product aslight purple paste which was purified by flash chromatography using 0 to40% EtOAc/hex to afford (S)-isopropyl2-(5-bromo-4-(4,4-dimethylpiperidin-1-yl)-2,6-dimethylpyridin-3-yl)-2-hydroxyacetate(6.7 g, 15.72 mmol, 84% yield) as colorless thick paste. ¹H NMR (500MHz, CDCl₃) δ 5.85 (d, J=5.7 Hz, 1H), 5.59 (d, J=7.4 Hz, 1H), 5.08 (dt,J=12.5, 6.3 Hz, 1H), 3.98-3.88 (m, 1H), 3.88-3.78 (m, 1H), 2.76-2.68 (m,1H), 2.67 (s, 3H), 2.64-2.58 (m, 1H), 2.57 (s, 3H), 1.73 (td, J=12.8,4.8 Hz, 1H), 1.65-1.59 (m, 1H), 1.47-1.35 (m, 2H), 1.27 (d, J=6.3 Hz,3H), 1.17 (d, J=6.1 Hz, 3H), 1.09 (s, 3H), 1.04 (s, 3H). LCMS(M+H)=414.6.

A stirred ice-cold yellow mixture of (S)-isopropyl2-(5-bromo-4-(4,4-dimethylpiperidin-1-yl)-2,6-dimethylpyridin-3-yl)-2-hydroxyacetate(6.7 g, 16.21 mmol) and 70% HClO₄ (2.2 mL, 25.6 mmol) in dichloromethane(400 mL) was saturated with isobutylene gas by bubbling through thereaction mixture (10 min). The reaction mixture was cloudy sealed in aseal tube, stirred for 24 h at rt. The reaction mixture was recooled ina −10° C. bath, bubbled additional isobutylene (˜15 min). The reactionmixture became a clear solution at this point. The tube was sealed andstirred at rt for 16 h. LCMs at this point showed incomplete reaction.So, the reaction mixture was cooled down to −30° C. and bubbledisobutene (˜15 min). After 24 h, reaction mixture was neutralized withsat. Na₂CO₃ (20 mL), organic layer separated and aqueous layer wasextracted with CH₂Cl₂ (25 mL). The combined organic layers were dried(MgSO₄), filtered, concentrated and purified on a ISCO 120 g column(EtOAc/hex: 0 to 40%) to afford (S)-isopropyl2-(5-bromo-4-(4,4-dimethylpiperidin-1-yl)-2,6-dimethylpyridin-3-yl)-2-(tert-butoxy)acetate(5.43 g, 9.83 mmol, 60.7% yield) as a viscous oil. ¹H NMR (500 MHz,CDCl₃) δ 6.26 (br. s., 1H), 5.09-4.97 (m, 1H), 4.06 (br. s., 1H), 3.51(br. s., 1H), 2.90 (br. s., 1H), 2.65 (s, 3H), 2.56 (s, 3H), 1.72-1.54(m, 3H), 1.47 (br. s., 1H), 1.37 (br. s., 1H), 1.23-1.20 (m, 12H), 1.15(d, J=6.1 Hz, 3H), 1.09 (br. s., 3H), 1.04 (br. s., 3H). LCMS(M+H)=471.3.

Preparation of intermediate(S)-2-(tert-butoxy)-2-(4-(4,4-dimethylpiperidin-1-yl)-2,6-dimethyl-5-(1,2,3,4-tetrahydroisoquinolin-6-yl)pyridin-3-yl)aceticacid from (S)-ethyl2-(5-bromo-4-(4,4-dimethylpiperidin-1-yl)-2,6-dimethylpyridin-3-yl)-2-(tert-butoxy)acetate

Step 1: To a mixture of (S)-ethyl2-(5-bromo-4-(4,4-dimethylpiperidin-1-yl)-2,6-dimethylpyridin-3-yl)-2-(tert-butoxy)acetate(500 mg),(2-(tert-butoxycarbonyl)-1,2,3,4-tetrahydroisoquinolin-6-yl)boronic acid(365 mg) and Cs₂CO₃ (715 mg) in 1,4-dioxane (25 mL) and water (5 mL) wasadded Pd(PPh₃)₄ (127 mg). The mixture was flushed with nitrogen and thenheated at 85° C. for 3 hours. The mixture was diluted with water (20 mL)and then extracted with EtOAc (2×20 mL). The organic layers werecombined, washed with brine and concentrated under vacuum to give acrude (S)-tert-butyl6-(5-(1-(tert-butoxy)-2-ethoxy-2-oxoethyl)-4-(4,4-dimethylpiperidin-1-yl)-2,6-dimethylpyridin-3-yl)-3,4-dihydroisoquinoline-2(1H)-carboxylatewhich was used in the next without purification. LCMS (M+H)⁺: 608.5.

Step 2: To a solution of (5)-tert-butyl6-(5-(1-(tert-butoxy)-2-ethoxy-2-oxoethyl)-4-(4,4-dimethylpiperidin-1-yl)-2,6-dimethylpyridin-3-yl)-3,4-dihydroisoquinoline-2(1H)-carboxylate(200 mg) in CH₂Cl₂ (20 mL) was added TFA (1 mL). The reaction wasstirred at room temperature for 3 hours. All the solvents were removedunder vacuum to give crude (S)-ethyl2-(tert-butoxy)-2-(4-(4,4-dimethylpiperidin-1-yl)-2,6-dimethyl-5-(1,2,3,4-tetrahydroisoquinolin-6-yl)pyridin-3-yl)acetatewhich was used in the next step without further purification. LCMS(M+H)⁺: 508.3.

Step 3: To a solution of (S)-ethyl2-(tert-butoxy)-2-(4-(4,4-dimethylpiperidin-1-yl)-2,6-dimethyl-5-(1,2,3,4-tetrahydroisoquinolin-6-yl)pyridin-3-yl)acetate(10 mg) in MeOH (1 mL) and THF (1 mL) was added sodium hydroxide (0.158mL, 1N). The reaction was stirred at 80° C. for 2 hours. The mixture wasacidified by 1N HCl to pH ˜4. All the solvents were removed under vacuumto give a residue was purified by preparative HPLC system to afford(S)-2-(tert-butoxy)-2-(4-(4,4-dimethylpiperidin-1-yl)-2,6-dimethyl-5-(1,2,3,4-tetrahydroisoquinolin-6-yl)pyridin-3-yl)aceticacid. LCMS (M+H)⁺: 480.3.

Preparation of Intermediate(S)-2-(tert-butoxy)-2-(4-(4,4-dimethylpiperidin-1-yl)-2,6-dimethyl-5-(1,2,3,4-tetrahydroisoquinolin-6-yl)pyridin-3-yl)aceticacid from (S)-isopropyl2-(5-bromo-4-(4,4-dimethylpiperidin-1-yl)-2,6-dimethylpyridin-3-yl)-2-(tert-butoxy)acetate

Step 1: To a mixture of (S)-isopropyl2-(5-bromo-4-(4,4-dimethylpiperidin-1-yl)-2,6-dimethylpyridin-3-yl)-2-(tert-butoxy)acetate(1.1 g),(2-(tert-butoxycarbonyl)-1,2,3,4-tetrahydroisoquinolin-6-yl)boronic acid(0.649 g) and Cs₂CO₃ (1.527 g) in 1,4-dioxane (40 mL) and water (8 mL)was added Pd(PPh₃)₄ (0.271 g). The mixture was flushed with nitrogen andthen heated at 85° C. for 5 hours. The mixture was diluted with water(50 mL) and then extracted with EtOAc (2×50 mL). The organic layers werecombined, washed with brine and concentrated under vacuum to give aresidue which was purified by silica gel chromatography(hexane/EtOAc=10:1 to 3:1) to give (S)-tert-butyl6-(5-(1-(tert-butoxy)-2-isopropoxy-2-oxoethyl)-4-(4,4-dimethylpiperidin-1-yl)-2,6-dimethylpyridin-3-yl)-3,4-dihydroisoquinoline-2(1H)-carboxylate.LCMS (M+H)⁺: 622.4.

Step 2: To a solution of (S)-tert-butyl6-(5-(1-(tert-butoxy)-2-isopropoxy-2-oxoethyl)-4-(4,4-dimethylpiperidin-1-yl)-2,6-dimethylpyridin-3-yl)-3,4-dihydroisoquinoline-2(1H)-carboxylate(420 mg) in CH₂Cl₂ (5 mL) was added TFA (1 mL). The reaction mixture wasstirred at room temperature for 4 hours. All the solvents were removedunder vacuum to give (S)-isopropyl2-(tert-butoxy)-2-(4-(4,4-dimethylpiperidin-1-yl)-2,6-dimethyl-5-(1,2,3,4-tetrahydroisoquinolin-6-yl)pyridin-3-yl)acetatewhich was used without further purification. LCMS (M+H)⁺: 522.3.

Step 3: To a solution of (S)-isopropyl2-(tert-butoxy)-2-(4-(4,4-dimethylpiperidin-1-yl)-2,6-dimethyl-5-(1,2,3,4-tetrahydroisoquinolin-6-yl)pyridin-3-yl)acetate(50 mg) in ethanol (4 mL) was added KOH (43.0 mg) and water (0.4 mL).The reaction mixture was heated at 85° C. for 6 hours. The mixture wasacidified by 1N HCl to pH=4. All the solvents were removed under vacuumto give crude(S)-2-(tert-butoxy)-2-(4-(4,4-dimethylpiperidin-1-yl)-2,6-dimethyl-5-(1,2,3,4-tetrahydroisoquinolin-6-yl)pyridin-3-yl)aceticacid which was used without purification. LCMS (M+H)⁺: 480.2.

General Procedure A for the Preparation of Compounds of Claim I, from(S)-ethyl or (S)-isopropyl2-(tert-butoxy)-2-(4-(4,4-dimethylpiperidin-1-yl)-2,6-dimethyl-5-(1,2,3,4-tetrahydroisoquinolin-6-yl)pyridin-3-yl)acetate

Step 1: DIEA or Na₂CO₃ or K₂CO₃ or Cs₂CO₃ or NaH (1-20 eq.) was addedinto a solution of (S)-ethyl or (S)-isopropyl2-(tert-butoxy)-2-(4-(4,4-dimethylpiperidin-1-yl)-2,6-dimethyl-5-(1,2,3,4-tetrahydroisoquinolin-6-yl)pyridin-3-yl)acetate(1 eq.) and an electrophile (1-20 eq.) in acetonitrile or THF or DMF ordioxane. The reaction was carried out at room temperature to 150° C. fora period of 10 minutes to 72 hours. After removal of solvents undervacuum, the residue was used as is or purified by the preparative HPLCsystem.

Step 2: To a solution of the product from the step 1 (1 eq.) in MeOH orEtOH and/or THF (volume ratio 20:1 to 1:20) was added NaOH or KOH (1 to100 eq.). The reaction was carried out at room temperature to reflux fora period of 10 minutes to 72 hours. The mixture was acidified by 1N HClto pH ˜4. Removal of the solvents under vacuum gave a residue which waspurified by the preparative HPLC system.

General procedure B for the preparation of compounds of Claim I, from(S)-2-(tert-butoxy)-2-(4-(4,4-dimethylpiperidin-1-yl)-2,6-dimethyl-5-(1,2,3,4-tetrahydroisoquinolin-6-yl)pyridin-3-yl)aceticacid

DIEA or Na₂CO₃ or K₂CO₃ or Cs₂CO₃ or NaH (1-20 eq.) was added into asolution of(S)-2-(tert-butoxy)-2-(4-(4,4-dimethylpiperidin-1-yl)-2,6-dimethyl-5-(1,2,3,4-tetrahydroisoquinolin-6-yl)pyridin-3-yl)aceticacid (1 eq.) and an electrophile (1-20 eq.) in acetonitrile or THF orDMF or dioxane. The reaction was carried out at room temperature to 150°C. for a period of 10 minutes to 72 hours. The mixture was diluted withEtOAc, washed with water, and dried over MgSO₄. After removal ofsolvents under vacuum, the residue was purified by the preparative HPLCsystem.

LCMS Method Compound (M + H)⁺ B(S)-2-(5-(2-(benzofuro[3,2-d]pyrimidin-4-yl)-1,2,3,4- 648.1tetrahydroisoquinolin-6-yl)-4-(4,4-dimethylpiperidin-1-yl)-2,6-dimethylpyridin-3-yl)-2-(tert-butoxy)acetic acid

B (S)-2-(tert-butoxy)-2-(4-(4,4-dimethylpiperidin-1-yl)-2,6- 657.1dimethyl-5-(2-(phenanthridin-6-yl)-1,2,3,4-tetrahydroisoquinolin-6-yl)pyridin-3-yl)acetic acid

B (S)-2-(tert-butoxy)-2-(5-(2-(4-chloro-7-methyl-9H- 695.1pyrimido[4,5-b]indol-2-yl)-1,2,3,4-tetrahydroisoquinolin-6-yl)-4-(4,4-dimethylpiperidin-1-yl)-2,6-dimethylpyridin-3-yl)acetic acid

B (S)-2-(5-(2-(1,10-phenanthrolin-2-yl)-1,2,3,4- 658.2tetrahydroisoquinolin-6-yl)-4-(4,4-dimethylpiperidin-1-yl)-2,6-dimethylpyridin-3-yl)-2-(tert-butoxy)acetic acid

B (S)-2-(5-(2-(5H-pyrimido[5,4-b]indol-4-yl)-1,2,3,4- 647.2tetrahydroisoquinolin-6-yl)-4-(4,4-dimethylpiperidin-1-yl)-2,6-dimethylpyridin-3-yl)-2-(tert-butoxy)acetic acid

B (S)-2-(5-(2-(benzo[4,5]thieno[2,3-d]pyrimidin-4-yl)-1,2,3,4- 664.2tetrahydroisoquinolin-6-yl)-4-(4,4-dimethylpiperidin-1-yl)-2,6-dimethylpyridin-3-yl)-2-(tert-butoxy)acetic acid

B (S)-2-(5-(2-(9H-pyrimido[4,5-b]indol-4-yl)-1,2,3,4- 647.2tetrahydroisoquinolin-6-yl)-4-(4,4-dimethylpiperidin-1-yl)-2,6-dimethylpyridin-3-yl)-2-(tert-butoxy)acetic acid

B (S)-2-(5-(2-(benzo[4,5]thieno[3,2-d]pyrimidin-4-yl)-1,2,3,4- 664.1tetrahydroisoquinolin-6-yl)-4-(4,4-dimethylpiperidin-1-yl)-2,6-dimethylpyridin-3-yl)-2-(tert-butoxy)acetic acid

B (S)-2-(tert-butoxy)-2-(4-(4,4-dimethylpiperidin-1-yl)-2,6- 649.2dimethyl-5-(2-(pyrido[3',2':4,5]furo[3,2-d]pyrimidin-4-yl)-1,2,3,4-tetrahydroisoquinolin-6-yl)pyridin-3-yl)acetic acid

B (S)-2-(tert-butoxy)-2-(4-(4,4-dimethylpiperidin-1-yl)-2,6- 714.2dimethyl-5-(2-(8-methyl-2-(methylthio)-8H-imidazo[4,5-d]thiazolo[5,4-b]pyridin-5-yl)-1,2,3,4-tetrahydroisoquinolin-6-yl)pyridin-3-yl)aceticacid

Methyl 2-(2-cyano-4-fluorophenoxy)acetate

To a stirred mixture of 5-fluoro-2-hydroxybenzonitrile (5 g, 36.5 mmol)and K₂CO₃ (5.54 g, 40.1 mmol) in acetone (100 mL) was added methylbromoacetate (1.464 ml, 15.88 mmol) at rt. After 18 h, the reactionmixture was diluted with hexanes (100 mL), filtered and concentrated togive methyl 2-(2-cyano-4-fluorophenoxy)acetate (7.57 g, 36.2 mmol, 99%yield) as which was used in the next step without purification. ¹H NMR(500 MHz, CDCl₃) δ 7.33 (dd, J=7.4, 3.2 Hz, 1H), 7.26 (ddd, J=9.3, 7.7,3.1 Hz, 1H), 6.86 (dd, J=9.2, 4.0 Hz, 1H), 4.79 (s, 2H), 3.84 (s, 3H).LCMS (M+H)=209.90.

Methyl 3-amino-5-fluorobenzofuran-2-carboxylate

To a stirred ice-cold solution of KOtBu (4.47 g, 39.8 mmol) in THF (100mL) was added dropwise a solution of methyl2-(2-cyano-4-fluorophenoxy)acetate (7.57 g, 36.2 mmol) in THF (30 mL).The addition flask was rinsed with THF (20 mL) and added to the reactionmixture. The resulting think yellow slurry was stirred for 2 h then coldbath removed. After 15 h at rt, the reaction mixture was concentratedand the residue was partitioned between EtOAc (200 mL) and 1M HCl (40mL). Aqueous layer was separated and organic layer washed with brine (25mL), dried (MgSO₄), filtered and concentrated to give methyl3-amino-5-fluorobenzofuran-2-carboxylate (7.02 g, 33.6 mmol, 93% yield)as yellow solid which was used in the next step without purification. ¹HNMR (500 MHz, DMSO-d₆) δ 7.78 (dd, J=8.7, 2.8 Hz, 1H), 7.53 (dd, J=9.1,4.0 Hz, 1H), 7.35 (td, J=9.2, 2.8 Hz, 1H), 6.36 (s, 2H), 3.82 (s, 3H).LCMS (M+H)=209.90.

8-Fluorobenzofuro[3,2-d]pyrimidin-4(3H)-one

A mixture of methyl 3-amino-5-fluorobenzofuran-2-carboxylate (1 g, 4.78mmol) and ethyl formimidate, HCl (1.047 g, 9.56 mmol) in formamide (10mL) was heated at 90° C. for 5 h. LCMS at this point showed very littleproduct. So, heated at 180° C. for 3.5 h. Then, cooled, diluted withwater (20 mL), filtered, washed with acetonitrile (5 mL) and air driedto afford 8-fluorobenzofuro[3,2-d]pyrimidin-4(3H)-one (0.86 g, 4.21mmol, 88% yield) as brown powder which was used in the next step withoutpurification. ¹H NMR (500 MHz, DMSO-d₆) δ 12.79 (br.s, 1H), 8.26 (s,1H), 7.91 (dd, J=9.1, 3.9 Hz, 1H), 7.86 (dd, 2.8 Hz, 1H), 7.56 (td,J=9.2, 2.8 Hz, 1H). LCMS (M+H)=204.90.

4-Chloro-8-fluorobenzofuro[3,2-d]pyrimidine

To a stirred solution of oxalyl chloride (0.645 ml, 7.37 mmol) in1,2-dichloroethane (25 mL) was added dropwise DMF (0.571 ml, 7.37 mmol)at rt over 5 min. After vigorous gas evolution had ceased,8-fluorobenzofuro[3,2-d]pyrimidin-4(3H)-one (0.86 g, 4.21 mmol) wasadded and the mixture was heated at reflux for 1 h. Then, cooled, washedwith sat Na₂CO₃ (10 mL), dried (MgSO₄), filtered, concentrated andpurified by Biotage using 0-40% EtOAc/Hex to afford4-chloro-8-fluorobenzofuro[3,2-d]pyrimidine (0.4647 g, 2.088 mmol, 49.6%yield) as white solid. ¹H NMR (500 MHz, CDCl₃) δ 9.03 (s, 1H), 7.96-7.92(m, 1H), 7.76-7.72 (m, 1H), 7.55-7.49 (m, 1H). LCMS (M+H)=222.85.

(S)-Isopropyl2-(tert-butoxy)-2-(4-(4,4-dimethylpiperidin-1-yl)-5-(2-(8-fluorobenzofuro[3,2-d]pyrimidin-4-yl)-1,2,3,4-tetrahydroisoquinolin-6-yl)-2,6-dimethylpyridin-3-yl)acetate

A clear solution of (S)-isopropyl2-(tert-butoxy)-2-(4-(4,4-dimethylpiperidin-1-yl)-2,6-dimethyl-5-(1,2,3,4-tetrahydroisoquinolin-6-yl)pyridin-3-yl)acetate(0.261 g, 0.5 mmol), DIEA (0.131 ml, 0.750 mmol) and4-chloro-8-fluorobenzofuro[3,2-d]pyrimidine (0.134 g, 0.600 mmol) in1,4-dioxane (10 mL) was heated at 100° C. for 2 h. Then, the reactionmixture was loaded to the silica gel column and purified by Biotageusing 10-100% EtOAc/Hex (15 CV) to afford (S)-isopropyl2-(tert-butoxy)-2-(4-(4,4-dimethylpiperidin-1-yl)-5-(2-(8-fluorobenzofuro[3,2-d]pyrimidin-4-yl)-1,2,3,4-tetrahydroisoquinolin-6-yl)-2,6-dimethylpyridin-3-yl)acetate(0.3197 g, 0.452 mmol, 90% yield) as white solid. LCMS (M+H)=708.20.

Compound 11

(S)-2-(tert-Butoxy)-2-(4-(4,4-dimethylpiperidin-1-yl)-5-(2-(8-fluorobenzofuro[3,2-d]pyrimidin-4-yl)-1,2,3,4-tetrahydroisoquinolin-6-yl)-2,6-dimethylpyridin-3-yl)aceticacid

A mixture of (S)-isopropyl2-(tert-butoxy)-2-(4-(4,4-dimethylpiperidin-1-yl)-5-(2-(8-fluorobenzofuro[3,2-d]pyrimidin-4-yl)-1,2,3,4-tetrahydroisoquinolin-6-yl)-2,6-dimethylpyridin-3-yl)acetate(0.31 g, 0.438 mmol) and 10M NaOH (0.438 ml, 4.38 mmol) in EtOH (10 mL)was refluxed for 9 h. Then, cooled, neutralized with 1M HCl (4.5 mL),diluted with EtOAc (50 mL), washed with water (3×10 mL), brine (10 mL),dried (Na₂SO₄), filtered and concentrated to to afford(S)-2-(tert-butoxy)-2-(4-(4,4-dimethylpiperidin-1-yl)-5-(2-(8-fluorobenzofuro[3,2-d]pyrimidin-4-yl)-1,2,3,4-tetrahydroisoquinolin-6-yl)-2,6-dimethylpyridin-3-yl)aceticacid (0.3027 g, 0.441 mmol, 100% yield) as off-white solid. LCMS(M+H)=666.2.

Methyl 2-(2-cyano-3-fluorophenoxy)acetate

To a stirred mixture of 2-fluoro-6-hydroxybenzonitrile (2.178 g, 15.88mmol) and K₂CO₃ (2.415 g, 17.47 mmol) in acetone (100 mL) was addedmethyl bromoacetate (1.464 ml, 15.88 mmol) at rt. After 18 h, thereaction mixture was diluted with hexanes, filtered and concentrated togive methyl 2-(2-cyano-3-fluorophenoxy)acetate (3.30 g, 15.78 mmol, 99%yield) as white solid which was used in the next step withoutpurification. ¹H NMR (500 MHz, CDCl₃) δ 7.54-7.48 (m, 1H), 6.87 (td,J=8.4, 0.7 Hz, 1H), 6.65 (d, J=8.7 Hz, 1H), 4.82 (s, 2H), 3.84 (s, 3H).LCMS (M+H)=209.95.

Methyl 3-amino-4-fluorobenzofuran-2-carboxylate

To a stirred solution of KOtBu (1.947 g, 17.35 mmol) in THF (50 mL) wasadded a solution of methyl 2-(2-cyano-3-fluorophenoxy)acetate (3.3 g,15.78 mmol) in THF (20 mL) over 5 min at rt. The addition flask wasrinsed with THF (10 mL) and added to the reaction mixture. The resultingthink yellow slurry was stirred for 4 h, then the reaction mixture wasquenched with 1M HCl (18 mL), diluted with EtOAc (200 mL), washed withwater (50 mL), brine (25 mL), dried (MgSO₄), filtered and concentratedto give methyl 3-amino-4-fluorobenzofuran-2-carboxylate (3.2797 g, 15.68mmol, 99% yield) as light brown solid which was used in the next stepwithout purification. ¹H NMR (500 MHz, DMSO-d₆) δ 7.51 (td, J=8.3, 5.7Hz, 1H), 7.37 (d, J=8.4 Hz, 1H), 7.08 (dd, J=10.1, 8.0 Hz, 1H), 6.08 (s,2H), 3.84 (s, 3H). LCMS (M+H)=209.90.

9-Fluorobenzofuro[3,2-d]pyrimidin-4(3H)-one

A mixture of methyl 3-amino-4-fluorobenzofuran-2-carboxylate (1 g, 4.78mmol) and ethyl formimidate, HCl (1.047 g, 9.56 mmol) in formamide (10mL) was heated at 180° C. for 5 h. Then, allowed to stand at rtovernight and the resulting thick slurry was diluted with water (20 mL),filtered, washed with acetonitrile (5 mL) and air dried to afford9-fluorobenzofuro[3,2-d]pyrimidin-4(3H)-one (0.60 g, 2.94 mmol, 61.5%yield) as brown powder which was used in the next step withoutpurification. ¹H NMR (500 MHz, DMSO-d₆) δ 12.96 (br. s., 1H), 8.27 (s,1H), 7.74-7.68 (m, 2H), 7.37-7.31 (m, 1H). LCMS (M+H)=204.90.

4-Chloro-9-fluorobenzofuro[3,2-d]pyrimidine

To a stirred solution of oxalyl chloride (0.515 ml, 5.88 mmol) in1,2-dichloroethane (20 mL) was added DMF (0.455 ml, 5.88 mmol) over 5min at rt. After 10 min, 4-chloro-9-fluorobenzofuro[3,2-d]pyrimidine wasadded to the resulting reaction mixture and heated at reflux for 1 h.Then, the reaction mixture was cooled, washed with sat Na₂CO₃ (5 mL),dried (Na₂SO₄), filtered and concentrated to give4-chloro-9-fluorobenzofuro[3,2-d]pyrimidine as brown solid which wasused in the next step without purification. ¹H NMR (500 MHz, CDCl₃) δ9.09 (s, 1H), 7.77 (td, J=8.3, 5.4 Hz, 1H), 7.59 (dd, J=8.4, 0.6 Hz,1H), 7.29-7.24 (m, 1H). LCMS (M+H)=222.85.

(S)-Isopropyl2-(tert-butoxy)-2-(4-(4,4-dimethylpiperidin-1-yl)-5-(2-(9-fluorobenzofuro[3,2-d]pyrimidin-4-yl)-1,2,3,4-tetrahydroisoquinolin-6-yl)-2,6-dimethylpyridin-3-yl)acetate

A mixture of (S)-isopropyl2-(tert-butoxy)-2-(4-(4,4-dimethylpiperidin-1-yl)-2,6-dimethyl-5-(1,2,3,4-tetrahydroisoquinolin-6-yl)pyridin-3-yl)acetate(0.261 g, 0.5 mmol), 4-chloro-9-fluorobenzofuro[3,2-d]pyrimidine (0.134g, 0.600 mmol) and DIEA (0.131 ml, 0.750 mmol) in 1,4-dioxane (10 mL)was heated at 100° C. for 2 h. Then, the reaction mixture was loaded tosilica gel column and purified by Biotage using 10-100% EtOAc/Hex toafford (S)-isopropyl2-(tert-butoxy)-2-(4-(4,4-dimethylpiperidin-1-yl)-5-(2-(9-fluorobenzofuro[3,2-d]pyrimidin-4-yl)-1,2,3,4-tetrahydroisoquinolin-6-yl)-2,6-dimethylpyridin-3-yl)acetate(0.294 g, 0.415 mmol, 83% yield) as white solid. LCMS (M+H)=708.25.

Compound2 12 and 13

(S)-2-(tert-Butoxy)-2-(4-(4,4-dimethylpiperidin-1-yl)-5-(2-(9-ethoxybenzofuro[3,2-d]pyrimidin-4-yl)-1,2,3,4-tetrahydroisoquinolin-6-yl)-2,6-dimethylpyridin-3-yl)aceticacid and(S)-2-(tert-butoxy)-2-(4-(4,4-dimethylpiperidin-1-yl)-5-(2-(9-fluorobenzofuro[3,2-d]pyrimidin-4-yl)-1,2,3,4-tetrahydroisoquinolin-6-yl)-2,6-dimethylpyridin-3-yl)aceticacid

A solution of (S)-isopropyl2-(tert-butoxy)-2-(4-(4,4-dimethylpiperidin-1-yl)-5-(2-(9-fluorobenzofuro[3,2-d]pyrimidin-4-yl)-1,2,3,4-tetrahydroisoquinolin-6-yl)-2,6-dimethylpyridin-3-yl)acetate(0.294 g, 0.415 mmol) and 10 NaOH (0.415 ml, 4.15 mmol) in EtOH (10 mL)was refluxed for 12 h. Then, cooled, neutralized with 1M HCl (4 mL),diluted with EtOAc (50 mL), washed with water (3×10 mL), brine (10 mL),dried (Na₂SO₄), filtered, concentrated and purified by prep-HPLC toafford(S)-2-(tert-butoxy)-2-(4-(4,4-dimethylpiperidin-1-yl)-5-(2-(9-ethoxybenzofuro[3,2-d]pyrimidin-4-yl)-1,2,3,4-tetrahydroisoquinolin-6-yl)-2,6-dimethylpyridin-3-yl)aceticacid (0.0838 g, 0.121 mmol, 29.2% yield) as solid, LCMS (M+H)=692.2, and(S)-2-(tert-butoxy)-2-(4-(4,4-dimethylpiperidin-1-yl)-5-(2-(9-fluorobenzofuro[3,2-d]pyrimidin-4-yl)-1,2,3,4-tetrahydroisoquinolin-6-yl)-2,6-dimethylpyridin-3-yl)aceticacid (0.1074 g, 0.161 mmol, 38.8% yield), LCMS (M+H)=666.2.

Compound 14

(S)-2-(tert-Butoxy)-2-(4-(4,4-dimethylpiperidin-1-yl)-2,6-dimethyl-5-(2-(8-methyl-5H-pyrimido[5,4-b]indol-4-yl)-1,2,3,4-tetrahydroisoquinolin-6-yl)pyridin-3-yl)aceticacid

A solution of (S)-isopropyl2-(tert-butoxy)-2-(4-(4,4-dimethylpiperidin-1-yl)-2,6-dimethyl-5-(1,2,3,4-tetrahydroisoquinolin-6-yl)pyridin-3-yl)acetate(0.130 g, 0.25 mmol), 4-chloro-8-methyl-5H-pyrimido[5,4-b]indole (0.082g, 0.375 mmol) and DIEA (0.044 ml, 0.250 mmol) in DMF (5 mL) was heatedat 140° C. for 48 h. Then, cooled, diluted with ether (50 mL), washedwith water (3×5 mL), brine (5 mL), dried (Na₂SO₄), filtered andconcentrated to give crude (S)-isopropyl2-(tert-butoxy)-2-(4-(4,4-dimethylpiperidin-1-yl)-2,6-dimethyl-5-(2-(8-methyl-5H-pyrimido[5,4-b]indol-4-yl)-1,2,3,4-tetrahydroisoquinolin-6-yl)pyridin-3-yl)acetatewhich was used in the next step without purification.

A mixture of crude (S)-isopropyl2-(tert-butoxy)-2-(4-(4,4-dimethylpiperidin-1-yl)-2,6-dimethyl-5-(2-(8-methyl-5H-pyrimido[5,4-b]indol-4-yl)-1,2,3,4-tetrahydroisoquinolin-6-yl)pyridin-3-yl)acetateand 10 NaOH (0.250 ml, 2.500 mmol) in EtOH (5 mL) was refluxed for 22 h.Then, cooled and purified by prep-HPLC to afford(S)-2-(tert-butoxy)-2-(4-(4,4-dimethylpiperidin-1-yl)-2,6-dimethyl-5-(2-(8-methyl-5H-pyrimido[5,4-b]indol-4-yl)-1,2,3,4-tetrahydroisoquinolin-6-yl)pyridin-3-yl)aceticacid (0.10 g, 0.151 mmol, 60.5% yield).

4-Chloro-5-ethyl-8-methyl-5H-pyrimido[5,4-b]indole

A mixture of 4-chloro-8-methyl-5H-pyrimido[5,4-b]indole (0.05 g, 0.230mmol), Cs₂CO₃ (0.299 g, 0.919 mmol), iodoethane (0.093 ml, 1.149 mmol)and 4A molecular sieves (0.5 g) in acetone was refluxed for 2 h. Then,the reaction mixture was filtered through plug of celite, concentratedand the crude 4-chloro-5-ethyl-8-methyl-5H-pyrimido[5,4-b]indole wasused in the next step without purification. LCMS (M+H)=245.90.

Compound 15

(S)-2-(tert-Butoxy)-2-(4-(4,4-dimethylpiperidin-1-yl)-5-(2-(5-ethyl-8-methyl-5H-pyrimido[5,4-b]indol-4-yl)-1,2,3,4-tetrahydroisoquinolin-6-yl)-2,6-dimethylpyridin-3-yl)aceticacid

A solution of (S)-isopropyl2-(tert-butoxy)-2-(4-(4,4-dimethylpiperidin-1-yl)-2,6-dimethyl-5-(1,2,3,4-tetrahydroisoquinolin-6-yl)pyridin-3-yl)acetate(0.052 g, 0.1 mmol), 4-chloro-5-ethyl-8-methyl-5H-pyrimido[5,4-b]indole(0.057 g, 0.23 mmol) and DIEA (0.026 ml, 0.150 mmol) in DMF (3 mL) washeated at 120° C. for 40 h. Then, cooled, diluted with ether (25 mL),washed with water (3×5 mL), brine (5 mL), dried (Na₂SO₄), filtered andconcentrated to afford crude (S)-isopropyl2-(tert-butoxy)-2-(4-(4,4-dimethylpiperidin-1-yl)-5-(2-(5-ethyl-8-methyl-5H-pyrimido[5,4-b]indol-4-yl)-1,2,3,4-tetrahydroisoquinolin-6-yl)-2,6-dimethylpyridin-3-yl)acetateas brown paste which was used in the next step without purification.

Then, EtOH (2 mL) and 10M NaOH (0.100 ml, 1.000 mmol) were added andstirred for 24 h at reflux. The reaction mixture was cooled and purifiedby prep-HPLC to afford(5)-2-(tert-butoxy)-2-(4-(4,4-dimethylpiperidin-1-yl)-5-(2-(5-ethyl-8-methyl-5H-pyrimido[5,4-b]indol-4-yl)-1,2,3,4-tetrahydroisoquinolin-6-yl)-2,6-dimethylpyridin-3-yl)aceticacid (0.0355 g, 0.052 mmol, 51.5% yield) as brown solid. LCMS(M+H)=689.2.

Biological Methods

Inhibition of HIV Replication:

A recombinant NL-RLuc proviral clone was constructed in which a sectionof the nef gene from NL4-3 was replaced with the Renilla Luciferasegene. This virus is fully infectious and can undergo multiple cycles ofreplication in cell culture. In addition, the luciferous reporterprovides a simple and easy method for quantitating the extent of virusgrowth and consequently, the antiviral activity of test compounds. Theplasmid pNLRLuc contains the proviral NL-Rluc DNA cloned into pUC18 atthe PvuII site. The NL-RLuc virus was prepared by transfection of 293Tcells with the plasmid pNLRLuc. Transfections were performed using theLipofectAMINE PLUS kit from Invitrogen (Carlsbad, Calif.) according tothe manufacturer and the virus generated was titered in MT-2 cells. Forsusceptibility analyses, the titrated virus was used to infect MT-2cells in the presence of compound, and after 5 days of incubation, cellswere processed and quantitated for virus growth by the amount ofexpressed luciferase. Assay media was RPMI 1640 supplemented with 10%heat inactivated fetal bovine serum (FBS), 100 units/ml penicillin G/100units/ml streptomycin, 10 mM HEPES buffer pH 7.55 and 2 mM L-glutamine.The results from at least 2 experiments were used to calculate the EC₅₀values. Luciferase was quantitated using the Dual Luciferase kit fromPromega (Madison, Wis.). Susceptibility of viruses to compounds wasdetermined by incubation in the presence of serial dilutions of thecompound. The 50% effective concentration (EC₅₀) was calculated by usingthe exponential form of the median effect equation where(Fa)=1/[1+(ED₅₀/drug conc.)^(m)] (Johnson Va., Byington R T. InfectivityAssay. In Techniques in HIV Research. ed. Aldovini A, Walker B D. 71-76.New York: Stockton Press. 1990). Results are shown in Table 1. Activityequal to A refers to a compound having an EC₅₀≤100 nM, while B and Cdenote compounds having an EC₅₀ between 100 nM and 1 uM (B) or >1 uM(C).

TABLE 1 Compound EC₅₀ 1 0.001 2 0.031 3 0.005 4 0.003 5 0.024 6 0.005 70.005 8 0.004 9 0.001 10 ND 11 0.002 12 0.001 13 0.003 14 0.013 15 0.045ND = Not determined

It will be evident to one skilled in the art that the present disclosureis not limited to the foregoing illustrative examples, and that it canbe embodied in other specific forms without departing from the essentialattributes thereof. It is therefore desired that the examples beconsidered in all respects as illustrative and not restrictive,reference being made to the appended claims, rather than to theforegoing examples, and all changes which come within the meaning andrange of equivalency of the claims are therefore intended to be embracedtherein.

We claim:
 1. A compound of Formula I

wherein: R¹ is selected from hydrogen, alkyl, or cycloalkyl; R² istetrahydroisoquinolinyl substituted with 1 R⁶ substituent and issubstituted with 0-3 halo or alkyl substituents; R³ is selected fromazetidinyl, pyrrolidinyl, piperidinyl, piperazinyl, morpholinyl,homopiperidinyl, homopiperazinyl, or homomorpholinyl, and is substitutedwith 0-3 substituents selected from cyano, halo, alkyl, haloalkyl,alkoxy, and haloalkoxy; R⁴ is selected from alkyl or haloalkyl; R⁵ isalkyl; and R⁶ is selected from phenanthrolinyl, phenanthridinyl,pyridofuropyrimidinyl, imidazothiazolopyridinyl, benzofuropyrimidinyl,benzothienopyrimidinyl, or pyrimidoindolyl, and is substituted with 0-3substituents selected from cyano, halo, alkyl, haloalkyl, alkoxy,thioalkyl, and haloalkoxy; or a pharmaceutically acceptable saltthereof.
 2. A compound or salt of claim 1 where R² istetrahydroisoquinolin-6-yl substituted with 1 R⁶ substituent and issubstituted with 0-3 halo or alkyl substituents.
 3. A compound or saltof claim 1 where R³ is piperidinyl substituted with 0-3 substituentsselected from cyano, halo, alkyl, haloalkyl, alkoxy, and haloalkoxy. 4.A compound of Formula I

wherein: R¹ is selected from hydrogen, alkyl, or cycloalkyl; R² istetrahydroisoquinolin-6-yl substituted with 1 R⁶ substituent and issubstituted with 0-3 halo or alkyl substituents; R³ is selected fromazetidinyl, pyrrolidinyl, piperidinyl, piperazinyl, morpholinyl,homopiperidinyl, homopiperazinyl, or homomorpholinyl, and is substitutedwith 0-3 substituents selected from cyano, halo, alkyl, haloalkyl,alkoxy, and haloalkoxy; R⁴ is selected from alkyl or haloalkyl; R⁵ isalkyl; and R⁶ is selected from phenanthrolinyl, phenanthridinyl,pyridofuropyrimidinyl, imidazothiazolopyridinyl, benzofuropyrimidinyl,benzothienopyrimidinyl, or pyrimidoindolyl, and is substituted with 0-3substituents selected from cyano, halo, alkyl, haloalkyl, alkoxy,thioalkyl, and haloalkoxy; or a pharmaceutically acceptable saltthereof.
 5. A compound of Formula I

wherein: R¹ is selected from hydrogen, alkyl, or cycloalkyl; R² istetrahydroisoquinolinyl substituted with 1 R⁶ substituent and issubstituted with 0-3 halo or alkyl substituents; R³ is piperidinylsubstituted with 0-3 substituents selected from cyano, halo, alkyl,haloalkyl, alkoxy, and haloalkoxy; R⁴ is selected from alkyl orhaloalkyl; R⁵ is alkyl; and R⁶ is selected from phenanthrolinyl,phenanthridinyl, pyridofuropyrimidinyl, imidazothiazolopyridinyl,benzofuropyrimidinyl, benzothienopyrimidinyl, or pyrimidoindolyl, and issubstituted with 0-3 substituents selected from cyano, halo, alkyl,haloalkyl, alkoxy, thioalkyl, and haloalkoxy; or a pharmaceuticallyacceptable salt thereof.
 6. A pharmaceutical composition comprising acompound of claim
 1. 7. The composition of claim 6 further comprising atleast one other agent used for treatment of AIDS or HIV infectionselected from nucleoside HIV reverse transcriptase inhibitors,non-nucleoside HIV reverse transcriptase inhibitors, HIV proteaseinhibitors, HIV fusion inhibitors, HIV attachment inhibitors, CCR5inhibitors, CXCR4 inhibitors, HIV budding or maturation inhibitors, andHIV integrase inhibitors, and a pharmaceutically acceptable carrier. 8.The composition of claim 7 wherein the other agent is dolutegravir.
 9. Amethod for treating HIV infection comprising administering a compound ofclaim 1, or a pharmaceutically acceptable salt thereof, to a patient inneed thereof.
 10. The method of claim 9 further comprising administeringat least one other agent used for treatment of AIDS or HIV infectionselected from nucleoside HIV reverse transcriptase inhibitors,non-nucleoside HIV reverse transcriptase inhibitors, HIV proteaseinhibitors, HIV fusion inhibitors, HIV attachment inhibitors, CCR5inhibitors, CXCR4 inhibitors, HIV budding or maturation inhibitors, andHIV integrase inhibitors.
 11. The method of claim 10 wherein the otheragent is dolutegravir.